"So, I swear this began with me offering water and Band-Aids, and the next thing you know, I'm the Meredith Grey of Sherwood Forest. I'm sorry if stealing from my med school makes me a bad person."
"It doesn't. It actually makes you deeper than I thought."
—Mary Hamilton and Kate Kane[src]

Mary Hamilton (born May 17, 1995)[1] is a medical student at Gotham University and influencer-in-the-making who secretly runs an illegal clinic to help Gotham's impoverished communities. She is the daughter of the late Catherine Hamilton-Kane, the step-daughter of Jacob Kane, the step-sister of Kate Kane and a close friend of Luke Fox. Mary acted as a close ally and medical support to Batwoman since the beginning of the latter's vigilante activities. After revealing to Kate that she'd figured out her secret identity, Mary officially became a member of the Bat Team.


Original multiverse

Early life

Mary was born on May 17, 1995 in Gotham City to an unknown father and Catherine Hamilton, the heiress of the Hamilton Dynamics arms fortune.

9-year-old Mary in an article about her mother's marriage to Jacob Kane.

On May 25, 2004 when Mary was nine years old,[2] Catherine married Jacob Kane and she met her step-sister, Kate Kane.[3] However, being quite different from one another, the two never really managed to become close, despite Mary's best efforts at being friendly. Nonetheless, she was very close with her stepfather, who loved Mary like his own daughter.[4] Also, despite their seemingly nonexistent relationship, Mary looked up to Kate throughout her life, with Kate in turn growing fond and protective of her, albeit maintaining a tough facade.[5][6]

Mary attended Gotham Preparatory High School. After turning 16, she was taught by Kate how to drive even though Kate didn't have a driver's license. Once, their car was pulled over by some cops, but Kate charmed them into not giving her and Mary a ticket. Mary was asked to homecoming by Derrick Peters, only to be stood up at the dance, upsetting her. Kate then hunted Derrick down and locked him in a urinal to avenge her step-sister.[5]

Growing up, Mary became very active on social media, to the point of being considered sort of an influencer,[7] much to her mother's dismay.[3] At some point, she also underwent cosmetic surgery to model her cheekbones after the well-known influencer Mia Cortez.[8]

Sometime after graduating college, Mary enrolled in Gotham University as a medical student. Mary claimed it was only so she could find her "future husband", whom she wanted to be a rich doctor. In actuality though, Mary was very interested in medicine and secretly became an excellent student.[7] At Gotham University, she attended three classes taught by Dr. Ethan Campbell,[9] while a friend of hers studied Professor John Carr's cryptography courses.[10]

Secret clinic

At some point before 2018, Mary started to distribute water and Band-Aids to residents of the poor neighborhood of Bennett Ave.. Sympathetic towards the people's plight, she eventually began using her medical expertise and Gotham University's funds to open an illegal clinic in the area.[3]

Kidnapping of Sophie Moore

Mary attends the switching off of the Bat-Signal.

In late 2018, Mary attended the switching off of the Bat-Signal with her mother and stepfather, during which she took a selfie with a kid dressed as Batman. After Sophie Moore was kidnapped by Alice and her Wonderland gang, Mary called her step-sister, Kate, during her global travel to tell her what happened.

Later at the Kane penthouse, Mary and Catherine organized a surprise welcome-home party for Kate, during which the former talked her step-sister's ear off. When Kate wondered why Mary called her, Mary revealed that she accidentally came upon a box of pictures of Kate and Sophie's relationship, and thought Kate would want to be in Gotham for her. She was then pulled away by her mother to take a photo with a councilwoman.

Mary stitches up Kate's wounds at her illegal clinic.

The following day, Mary was working at her clinic when she found Kate left on the doorstep. Kate was brought in and Mary helped stitch up a wound on her arm. Mary explained all about her secret clinic while also tending to an old man, pleased when Kate complimented her actions. Later, a member of the Wonderland gang was brought into her clinic and somehow confessed Sophie's location, which Mary informed Kate of.

Mary listens to a child describing the Bat.

The next day, after the city believed that Batman had returned, Mary listened to a child at her clinic describe how the Bat flew. She was delighted at the possibility that Batman was once again protecting Gotham.[3]

Nearly killed by Alice

Breakfast at Kane penthouse.

The following day over breakfast, Mary watched a video of a baby turtle eating a strawberry and showed it to an annoyed Kate. When Kate again dismissed her father's suggestion of joining the Crows, Mary asked if it was because of Sophie, expressing her shock that Sophie was now married to a man and asking out loud what her actual sexual orientation was. Kate cut her off by revealing to Jacob her suspicious that Alice was actually her long-lost twin, Beth, shocking everyone.

Mary asks Kate to have dinner together.

Later that day, Mary was visited by Kate at her clinic in order to speak with one of Alice's men who was brought in last night, and gave him a coded message to deliver to his boss. After the man left, Mary asked Kate if she wanted to have dinner with her, since they hadn't been able to spend time together since Kate returned to Gotham. Kate accepted her invitation and they agreed to meet that evening out of the clinic.

Mary is attacked by Dodgson.

Mary waited a long time, but Kate did not show up for their appointment (being at a secret meeting with Alice). After a brief blackout in the building, Chuck Dodgson appeared and attacked Mary, intending to murder her on Alice's orders since the latter was jealous of Mary being Kate's "new sister". Mary managed to defend herself by stabbing Dodgson in the leg with a scalpel and locked herself in a closet. She was then saved by Batwoman, who revealed herself as the new Bat vigilante.

Mary confronts Kate about always favoring Beth.

The following morning, Mary was shaken from Dodgson's attack and instinctively pulled a gun on Kate when the latter came to visit her in her clinic. After calming down, Mary scolded Kate for ditching her, stating it was ironic why Alice attacked her because she felt Kate didn't consider her a sister at all. Kate insisted that wasn't true but Mary was skeptical and asked if Alice was "worth it". When Kate couldn't answer, Mary requested Kate to let Alice know that she "wasn't a threat" before walking away, upset.[11]

Mary confronted by Sophie.

After the incident, Mary spent several nights working late at her clinic. One morning, after having vaccinated a kid and rewarding her with a sweet for not crying after the shot, Mary returned to the Kane penthouse, pretending she spent the whole night partying. There, she was confronted by Sophie; Jacob assigned her to to Mary's protection due to the latter having become Alice's target.

Sophie escorts Mary at Gotham University.

Much to Mary's dismay and embarrassment, Sophie followed her the whole day, even during her classes at Gotham University. While doing her schoolwork, Mary commented that she couldn't find her "future husband" if Sophie kept following her around, proceeding to ask about her own marriage. Sophie avoided the question by asking instead about Kate and why she continued to refuse to join the Crows, to which Mary replied that it was because Sophie is one of them.

An awkward elevator trip.

Mary and her family attended Tommy Elliot's party at Elliot Tower. She and Sophie were riding together in an elevator when Kate entered. Mary complained to her step-sister about having a "baby-sitter" and she and Kate mutually commented between one another how annoying Sophie was. The elevator began a long ascent, dominated by an embarrassed silence.

Later at the party, Mary complained again to her mother about giving her a bodyguard, but Catherine stated it was inevitable since they lived in difficult times

Sophie helps Mary escape the elevator.

A few moments later, Jacob ordered his men to escort his family away after receiving a phone call from Alice. However, due to Tommy having planted bombs on three elevators in the tower, Mary found herself stuck in one of them alongside Sophie and Tyler. She watched the couple bicker about Sophie not having told Tyler that she knew Kate from Point Rock Academy, before the they managed to find a way to escape the elevator.

Mary saves a woman's life at Elliot Tower.

On their way out of Elliot Tower, Mary and Sophie ran into some people wounded by an explosion from the first elevator. Mary managed at first sight to locate a woman who wasn't adequately tended to, making a correct diagnosis of her condition and saving the woman's life, under the astonished gazes of a paramedic and Sophie. After Tommy was arrested, Mary recovered from the incident with a shock blanket and hot chocolate. She watched from afar as Kate was asked out by a bartender and noted Sophie's conflicted reaction.[7]

Assisting Batwoman

Batwoman brings Dodgson to Mary's clinic.

When Dodgson developed an infection due to his days of captivity at the hand of Batwoman, she brought him to Mary's clinic asking her to deal with his wound with the maximum discretion. Mary, declaring to be a "big fan" of the vigilante reluctantly accepted despite the man having attempted to kill her.

Mary tricks Dodgson into revealing some details of Alice's plan.

That evening, while he was handcuffed to the bed and drugged with morphine, Dodgson began hallucinating, calling for his boss and lover Alice. Hearing that, Mary decided to impersonate Alice in an attempt to extorting him part of the latter's villainous plan and prompting him to reveal her that a key component to it was a mysterious figure named "Mouse".

Mary after being complimented by Batwoman.

Later, Batwoman came back to the clinic asking Mary for Dodgson conditions and she claimed he was stable, also referring her what she had discovered regarding Alice's intentions, which prompted Batwoman to plant a subdermal transmitter on Dodgson in order to track him after he returned to Alice, while complimenting Mary for her work.[12]

Catherine confess her past deed to Mary.

The next day, during a walk by the river with her mother, Catherine revealed to Mary that years ago she made Jacob believe that Beth was dead by making pass deer bone fragments for Beth's and paying the coroner to manipulate the DNA test, so that he and Kate would move on. Mary was deeply unsettled by her mother's statement, deeming it as an "horrible thing", and walked away from her in a state of shock.

Mary stormed drunk into Wayne Tower and is taken under the concierge's custody.

Distressed, Mary got completely drunk and stormed into the Wayne Tower demanding to speak with her step-sister, being then taken under the custody of the building concierge and escorted to the head of security, Luke Fox who introduced to her as Kate's assistant explaining she was not there and that he can deliver a message to her if needed, to which Mary began a confusing explanation of which Luke understood only that her mother may or may not have killed a deer, prompting the girl to explain everything from the beginning.

Drunken Mary lashes out at Luke.

Mary spent the whole day at Wayne Tower complaining to Luke about being the daughter of the "Wicked Witch of Gotham". Upon realized that Alice was indeed Beth as Kate had believed, Mary asked Luke if Kate was with her, which he confirmed. Mary then bitterly lashed out at Luke over how Kate always favored her supposed dead twin over the former, even now that Beth had become a convicted serial killer.

Mary watches Luke's researches.

After a while, still drunken due to the alcoholic beverages kept in Bruce's office, she watched the researches Luke was doing about Arkham Asylum outbreak, discovering the authorities have covered up everything about it, then she noticed the footage about Alice being the Skin Pirate and get hungry of pizza. That evening, after ordering and eating a pizza box, Mary apologized to Luke for disturbing him all day and left the building, asking him to simply tell Kate that she was sorry.[13]

Sophie awakens in Mary's secret clinic.

Few nights later, after Sophie was wounded in a gunfire at 200 of Rucka Avenue, Batwoman brought her to Mary's clinic asking her to take care of her and prevent her from leaving the facility. Despite her skepticism she obeyed and nursed the woman back to health; after Sophie woke up she asked were she was, to which Mary revealed the truth about her illegal clinic then, noticing she was handcuffed, Sophie asked to be released and Mary replied it was due to Batwoman's order. Frustrated, Sophie stated that the reason why Batwoman didn't want her to leave was that she knew her real identity, however Mary replied that she had no interest in that knowledge.

Mary gives a box of ibuprofen and some warnings to Sophie.

Later, Sophie managed to free herself and was about to leave the clinic being intercepted by Mary, who gave her some medical advises and a box of ibuprofen, urging her not to reveal to her step-father about her clinic nor Batwoman's identity due to betray people was kinda becoming "her thing" and she shouldn't hurt Batwoman the way she hurt Kate several years ago.

Mary warns Batwoman that Sophie knows her identity.

Then, after Batwoman came to visit her, asking about Sophie, Mary explained she had let her go despite the fact she probably knew her identity and would reveal it to the Crows' commander. Despite she expected the vigilante to be angered, she was surprised when Batwoman thanked her for saving Sophie and quietly left.[14]

Family crisis

Catherine and Mary in a limousine.

After Jacob asked to divorce from Catherine, Mary reluctantly accompanied her mother to see the lawyers; while they were on limousine she stated that she had yet to forgive her and wished to be everywhere but there with her, Catherine said that she would have understood her action after becoming a mother as well, then she was called by Hamilton Dynamics and informed of their secret weapon's disappearance as well as Dean Deveraux's death.

Mary tries to talk with Kate about their family crisis.

Later that night, Mary introduced into the Wayne Tower once again thanks to the help of her friend Carl the receptionist, to whom she offered a Frappuccino. After reaching Bruce's former office in order to speak to Kate, she waved at Luke and introduced herself to Julia Pennyworth which Kate explained was her other assistant, after Mary commented on having two assistants in a real estate firm with no real estate, Kate told her that she was busy and that would have called her the following day, prompting Mary to ask if she was at least a little shaken about their family collapsing a moment before getting out of the building.

Kate and Mary put the beginning touches on their new gay bar.

The next day, Kate invited Mary at the first place she had bought with her firm, explaining her intention to open a gay bar in it as retaliation to Alessandro's homophobia, to which Mary gladly suggested to be the one to deal with design.[4]

Mary tries to convince Kate to come with her to the annual Humanitarian Ball.

Mary convinced her step-father (actually Mouse in disguise) to join her and her mother at Gotham's annual Humanitarian Ball, where Catherine would receive the Humanitarian Award. She then approached Kate at their bar with a suit for her step-sister to wear at the event but Kate declined, unable to forgive Catherine for her actions. Mary pointed out that Kate spent the past few months forgiving Alice, to which Kate claimed it was different as Alice was "[her] family". Mary was deeply hurt by Kate's words, which implied she still didn't count as her step-sister's family. Brushing off Kate's attempts to explain, Mary left their bar, revealing that Jacob had agreed to come to the ball for her sake.

A toast in Catherine's honor.

That night, she went to the Orpheum Theatre with "Jacob" and Catherine, making a toast of champagne in the latter honor while on their limousine. Then after in the middle of her speech Catherine started to reveal a series of crimes in front of the audience due to Alice blackmail (whose men had surrounded de building infiltrating the Crows) and subsequently collapsed, Mary help to transport her to the back of the stage and called the hospital while "Jacob" left stating that he was going to look for help.

Alice tells Mary and Catherine there's only enough antidote for one of them.

However, as the man leave Alice entered the room revealing that Catherine was poisoned with a Hamilton Dynamics toxin by Mouse posing as Jacob and that she got the antidote with her. After pouring the antidote into a teacup, Alice forced Catherine to apologize to her for the years of suffering she endured because of her deception then, having received said apology, she revealed that Mary was poisoned too and that there was only enough antidote for one of them.

Mary tries to revive her mother.

Obeying her mother's last wish, Mary took the antidote. She broke down in tears as Catherine declared that raising her daughter was the only good thing that she had done in her life; Catherine revealed she was aware about Mary's activities with her clinic, much to the latter's shock, and was proud of her. Catherine then succumbed to the poison and died in Mary's arms. Mary desperately performed CPR on Catherine in an attempt to revive her mother, to no avail.

Mary makes Kate realize that Beth wasn't worth it.

A heartbroken Mary returned to her clinic, where she was reached by Kate. However, Mary spitefully rejected her step-sister, stating that if Kate hadn't given Beth the benefit of doubt so many times, her mother would still be alive. Mary tearfully revealed how Catherine willingly gave up her life to save the former and pointed out that while her mother made mistakes, she didn't deserve to die the way she did. Mary asked Kate one more time if Alice was "worth it", prompting Kate to finally admit she was not. Mary simply responded it was too late and walked off.

After Kate left, Mary destroyed some items in her clinic in a rage as she broke down in grief.[15]

Anti-Monitor Crisis

During the Anti-Monitor Crisis, Mary as well as everyone in the multiverse except for the seven Paragons, was killed in an antimatter wave by the Anti-Monitor on December 10, 2019,[16] only to be restored a month later, after the Paragons and the Spectre created a new universe.[17]

New multiverse

Jacob's trial

Mary shuts down her social media accounts.

A week later, due to the several critics she received via social for her family and company's corruption, Mary decided to shut down all of her accounts recording a last live to explain all of her followers that it would be better for everyone.

Right as she was doing it, Kate entered her secret clinic asking once more how does she felt, however Mary answered with a series of snarky remarks on her twin sister's role in her mother murder.

Mary tells Kate how she is taking care of Jacob's trial.

Mary explained that she hired various team of lawyers, including Hewitt & Associates in order to take care of Jacob defense at the trial while Sophie has taken charge of a strike team to arrest Alice and Mouse, also stating that she was busy trying to find a plastic surgeon willing to testify that Mouse was wearing a mask made of skin grafts to pose as her adoptive father. As Kate asked Mary how could she help her, the latter respond telling her that she could ask her sister to stop desecrating her mother's grave daily, remembering that she knew Alice could have done something that evil, yet Kate choose to ignore her.

Mary calls Jacob in jail.

Later, Mary called Jacob in prison explaining that she managed to postpone his hearing for a week in order not to have it coincide with Valentine's Day, yet she still had difficulties in finding a professional to testify that "face exchange" could be possible. Jacob replied that she should talk with someone and that despite all the differences of opinion between him and her mother, he never stopped wanting to be her father, to which the latter responded that she had no time for feeling sorry for herself and that she needed to concentrate on what freeing him.

Mary talks to Dr. Campbell.

That evening, Mary visited Dr. Ethan Campbell after one of his classes at Gotham University asking him to be a witness in Jacob's trial, however the man politely dismissed the idea of a man completely resembling another as sci-fi, suggesting that the girl was still traumatized because of the event.

Mary dismantles her secret clinic.

While walking home and talking with Sophie via phone, Mary had the impression of seeing a woman who looked like Alice entering Gotham University and had her sent a strike team, however, few hours later Sophie went at Mary's clinic while she was dismantling it, having become disillusioned at her ability to save people due to losing her mom, and told her that they didn't find the villainess, thus suggesting that the girl was put under extreme duress and she needed to take time to cope with her loss and simply grief for her mother.

Mary and Kate reconcile.

The following day, Kate visited Mary in her clinic after the latter had made yet another unsuccessful call to a surgeon. Mary broke down in tears and, without saying a word, the step-sisters hugged and reconciled.[9]

Meeting Beth Kane's doppelgänger

Mary investigates the second Beth with Kate and Luke.

The following day, Sophie informed her that a woman who looked identical to Beth entered Kate's office and had a brief skirmish with the latter, deducing it was the same woman she saw at Gotham University, Mary went at Wayne Enterprises helping Luke and Kate to check the belongings that the mysterious woman left behind; after discovering the intruder's DNA perfectly matched that of Alice - who was still locked under Crows custody - Mary found the doppelgänger's 300 page dissertation on theoretical extragalactic astrophysics and cosmology, thus deciding to go asking Gotham University if someone knew this "Beth".

Mary helps Beth to pose as Alice.

Later, after Mouse kidnapped Kate asking Alice's release on exchange for her freedom and that of Bryan Akins and Steven Forbes and the other Beth offered to pretend to be Alice in order to save her, Mary helped the woman dress up to look the part of the villain and she was confused because the last time she had looked at Alice, her mom was dying in her arms after being poisoned. Beth told Mary that she couldn't help but feel guilty for this Earth's Beth causing all that harm to her as Alice, to which Mary pointed out she shouldn't feel that way as she was "nothing like that bitch".

Mary holds a birthday party for her step-sister.

Later that night, after Kate, the boys and Beth were all saved, Mary organized a surprise birthday party for her step-sister at the Hold Up together with Luke and Beth; there she told Kate that despite resenting Alice and never really understanding why she wanted to reach her before that day, but after meeting the other Beth she was starting to understand what she missed about her sister. Mary also correctly guessed the existence of the Multiverse, its collapse, and the birth of Earth-Prime, then dismissing it as an impossible idea and watched as, after blowing their cake's candles together with Kate, Beth started to get a splitting headache.[2]

Mary and Luke tries to sneak Beth through a Crows' checkpoint.

Mary and Luke immediately tried to transport Beth at the Gotham General Hospital but they were stopped at a checkpoint of the Crows, who were looking for Alice with the order to kill. They managed to avoid arrest thank to Batwoman's intervention however they are eventually forced to come back at the Wayne Tower, where Mary extracted a blood sample from Beth and analyzed it discovering that her blood cells were rapidly deteriorating, to which the latter theorized that the new Universe was literally not big enough for both her and Alice, who were sucking up life force from each other to stay alive; however Mary claimed that their degeneration would eventually kill them both in seven hours.

Mary analyzes Beth's blood.

Shocked, Kate ask Luke, Mary and Beth herself to find a solution as Gotham's most intelligent people, while she tried to stop Sophie's hunt for Alice through all the city. Later, Mary went to her clinic to consult some of her books, however she was approached by Alice, who reminded her of the antidote she drank the night she poisoned her and her mother, which was still in her blood and could cure any disease.

Mary tells Alice she doesn't deserve to live.

The villainess then knocked Mary down and extracted a sample of her blood, however she woke up and, taking advantage of another of Alice's headaches, attacked her eventually managing to subdue and handcuffing her to a cot in her clinic. Alice begged her to have that blood saying it was the only thing that could save her life, to which Mary replied she can't imagine someone less deserving of living.

Mary tells Kate to take her choice.

Then, Mary left her clinic and met with Kate out of the Wayne Tower in order to give her the syringe with her blood explaining that it could make one of the two women's life last longer and she could ever choose to save Beth, one of the most caring persons she met, or Alice, the psycho who killed her mother. Leaving the ultimate choice to her step-sister, Mary left the scene.[18]

Discovering Kate's secret

Kate, Luke and Mary discuss the aftermath of Beth's murder.

The following morning, Kate, Luke and Mary discussed the aftermath of Beth's murder; Mary stated that it wasn't supposed to be her the one to die, and tried to comfort Luke about not having been able to protect her. He replied that they need to figure out who the shooter was, prompting Mary to point out they need to prepare themselves for the real Alice, as the Crows now believe her to be dead and that she would probably have a grudge against Kate since she choose to save her doppelgänger over her. Then, Mary told Kate that nevertheless of all the consequences she made the right choice, however Kate commented that it doesn't matter as the wrong Beth survived.

Mary checks Kate's blood.

The next day, after confronting Nocturna, Kate had her blood checked by Mary at her clinic, telling her it was because she suspected of having a flu, to which Mary suggested it may be psychosomatic as a manifestation of her guilt for choosing Beth over Alice. After the analysis were completed and she found ketamine into Kate's blood, Mary asked her step-sister how it could be possible, to which Kate was quick to replied that she drunk heavily during her real estate classes as "no one wants to take them sober", before leaving the clinic and a perplexed Mary behind.

Sophie and Mary at the Hold Up inauguration.

That night, she went at the opening party of the Hold Up, noticing Sophie among the crowd and telling her to loosen up and enjoy the party despite the agent's claims she was there to work as for Commander Kane's order; she offered Sophie some vodka and persuaded her into flirting with Elle Scantlin, leaving them alone with an excuse after they started to chat.

Mary is rescued from Andi Ostergaard by Luke.

After this, however, Mary was approached by Andi Ostergaard a woman who followed her on Instagram and had a crush on her, assuming she was a lesbian too, Andi tried to hit on Mary, who was then "rescued" by Luke; when Andi asked if he was her boyfriend Mary quickly lied saying it was her boyfriend's brother, prompting Andi to leave. Luke remarked that she was very firm into stating that he wasn't her boyfriend, to which she blushed a little and simply complimented his phosphorescent tie. After Luke departed to "assist" Kate, Mary looked at the facts that he seem to work 24/7 for her and had an earphone in a suspicious way.

Batwoman rescues Mary from Nocturna's captivity.

When Mary left the party and headed back home, she noticed a drunk woman in the corner and tried to help her, however as soon as she approached the woman Mary was attacked by Nocturna, who took her to the Gotham Cathedral Church and drained her blood aiming at the Desert Rose-cure Alice gave her. The girl was luckily saved by Batwoman, who managed to defeat Nocturna, and unexpectedly Alice, who gave her a blood transfusion.

Mary is "rescued" from Nocturna and taken back to her clinic.

Brought back to her clinic in Bennett Ave., she was visited by her step-sister in the following morning and stated she felt fine, enjoying the thought that Batwoman bought her some cookies after saving her and explaining that she does some test in her own blood but found anything abnormal no more.

Mary realizes Kate's identity.

Later, hearing Nocturna used ketamine-injecting teeth on her victims at Vesper Fairchild's talk show, Mary remembered that Sophie herself told her that Batwoman had been bitten by the villainess during their first fight, so she put the pieces together flashing about Luke's behavior and Batwoman's public coming out, which drove her to finally realize about Kate's secret identity.[1]

Mary meets Sophie at the Hold Up.

The following morning Mary met Sophie at the Hold Up and, seeing how happy she seemed despite being suspended from her job, asked what was happening, to which the latter made her promise not to tell it to anyone and then revealed that she kissed Batwoman, prompting Mary to ask her if she knew her identity. Sophie replied she didn't and asked the same question, but Mary kept the secret over what she have just discovered.

Mary gives Kate information on Gotham's influencers.

Later, Kate visited her asking her how does she felt since the Serial Slasher started targeting influencers like Mia Cortez and Kimberly Wright, thus making her a potential target. Mary stated that it would be hard as most of her followers abandoned her after her mother publicly confessed her crimes, she listed Kate all the influencers' connections and gossip, explaining many had undergone cosmetic surgery by Dr. Campbell and persistently suggesting that she can help her with her knowledge in the field or her medical skills, however Kate declined and told her to simply be careful.

Mary helps Batwoman identify Veronica May.

That night, after having visited Duela's home and found pictures of all of her victims but failing to recognize the next, Kate went back to Mary under the persona of Batwoman. The girl told her that she knew she would have came to her asking help and, after Batwoman asked her how Mary replied that she was observant and intelligent, skills which are too often underestimated. She then correctly recognize the picture of the next victim as Veronica May before changing name and having cosmetic surgery, she also explained where to find her and, after the vigilante stormed off, Mary go take a take away pizza at the Slice of Gotham.

Mary talks with Alice at her clinic.

Coming back at her clinic, Mary found Alice and her Wonderland gang stealing medical supplies, her self-proclaimed "sister" explained that she was collecting her debt since she owed her life to her after the blood transfusion with whom she saved Mary from Nocturna. When Alice asked her if Batwoman hasn't told it to her, Mary was puzzled and asked if she knew who she is, to which the villainess told her she did, pointing out that if she hadn't told it to Mary too, maybe they weren't as close as she believed.

Mary tells Kate she hopes that one day she would trust her.

The next morning, before the Hold Up opened, Mary met there with Kate and asked her if she was troubled by something, remembering she could talk about everything with her; Kate simply replied that she failed an important business deal, however Mary asked her if she remembered the first time in which she was transported to her clinic, stating that nor even for a single second she thought that Kate would have reported her to the police or told her to stop, because she trusted her, adding that she hoped that one day Kate would trust her in the same way.[8]

Mary and Luke get information from Mad Dog.

After spreading some flyers that announced a $1,000 reward for anyone with information about a car spotted by some camera near Twin Pines Inn the night of Beth's murder, Mary was approached at her clinic by an individual who introduced himself as Mad Dog, who claimed he have saw said car in a junkyard in the Green; immediately the girl called Luke Fox and asked Mad Dog to tell him the same thing since they believe said car belong to Beth's killer. Despite Mad Dog's thuggish appearance and rough attitude lead Luke not to trust him, Mary believed him and gave him his reward.

Mary and Luke in the junkyard.

Then, the two went to the junkyard indicated by the man, finding the car and ultimately proving Mad Dog to be trustworthy; Luke apologized for having doubted Mary's instinct and immediately opened the trunk, finding the rifle that killed Beth. Right in that moment, Mary received an incoming call from an unknown number and, after she answer it, she discovered it was Batwoman seeking her help to save a "bad guy" who just stabbed his own throat. The girl managed to explain via phone how to close the wound with a stapler and, after Batwoman thanked her she told her that she'd be there for her in anytime. Then, as for a sort of spite towards Luke, who insisted on not using "gadgets" during their investigations so as not to be discovered, when he asked her what Batwoman wanted at the phone, Mary replied that it was a "doctor-vigilante secret".

Mary searches the Batcave's entrance.

Later that evening, back at the Wayne Tower, while Luke tried to track the car's license plate, Mary tried to find the Batcave's entrance by randomly moving books in the library, only to lie that she was interest in said books after Luke asked her what she was doing. Then, when Luke managed to find out who the car was registered to, she was as surprised as him to find out that it was Mabel Cartwright, who died at the same time her son went into hiding.[19]

Mary at Luke's side at Gotham's Temple of Justice.

After discovering that Reggie Harris' post-conviction hearing was anticipated, Mary reached Luke at Gotham's Temple of Justice moments before it began, grabbed his hand and told him that, having lost a parent herself, she knew how he could feel about facing his father's killer. Luke thanked her to be there and, after she asked where his mother was, he explained she didn't made it as she was unable to stand the situation. Mary stayed at Luke's side for all the process and, after Judge Wellington accepted his appeal for a new trial setting Reggie free until that date, she tried to calm Luke telling him it wasn't over.

Mary meets Sophie and Julia at her clinic.

Later that evening, while coming back to her secret clinic she found there Sophie intent on tend Julia's arm and began assisting her. The two informed her that they were attacked by a hitman due to a bounty on Sophie's head, guessing that since she was investigating the cover-up of Lucius Fox's murder, that was the reason someone wanted her dead.

Mary panics after seeing Luke covered in blood.

Later that night Luke came to her clinic covered in blood and she panicked asking what happened to him, Luke reassured her explaining the blood wasn't his and that Reggie was killed in front of his eyes after telling him he was used as a scapegoat for someone who was probably rich enough to cover-up everything. Mary comforted him and then they both reflect that if Reggie wasn't Lucius killer the real murderer was still at large.[20]

Mary scold the Batwoman copycat.

After Batwoman disappear for a week, she started to treat the wounds of various impersonator of the heroine, especially a recurring one who one day came to her clinic after a celling fell on top of her breaking her ribs while she was helping people getting free from rubble after the Detonator blew up the Gotham International Bank. Mary severely scolded the woman for her behavior, despite stating that however her heart was on the right place; then the Batwoman copycat asked her if she knew where the real one was since she knew everyone in the city, prompting Mary to answer that she was the last person Batwoman would speak to.

Mary choose to stay at her patient's side.

Later, while the Detonator has two bomb planted on Bennett Ave., one on Bobby Reeves and the other under a building, Mary evacuate her clinic of all the people who can walk, helped by the Batwoman copycat and some of her improvised staff, however she decided not to leave the building due to not wanting to left her weaker patient behind. The Batwoman copycat stayed at her side and helped her to secure in the better way possible the remaining patients, yet both Mary and the woman were caught in the explosion.

Mary reveals to Kate that she knows she is Batwoman.

Having managed to survive with just some minor wound, Mary immediately began helping the other victims getting rid of the rubble, being soon reached by Kate, who had a panic attack after seeing the unconscious woman dressed as Batwoman. Mary told her step-sister that she knew about her secret identity and that it should have been obvious as Mary looked up to her through all her life. Kate replied that she was not a hero, to which Mary replied that the city needed her and she wasn't asking her to be a hero, but rather to keep going.

Kate tells Luke and Mary to work together.

The following morning, after the Detonator was arrested, Mary visited Kate at the Wayne Tower to shown her an article about Batwoman's return commenting how good she looked in the picture. Luke tried to deny that Batwoman and Kate are one and the same, to which both the girls replied that she knew the truth, prompting Luke to stubbornly keep denying it; thus Kate left, telling Mary and Luke to resolve it themselves.[5]

Member of the Bat Team

Mary holds a victory party for the Bat Team.

A week later, after the Bat Team successfully thwarted the plans of a human traffic ring, Mary held a party to them at Wayne Enterprises in order to celebrate the victory with champagne, and suggested some upgrades for the Batsuit, then after Kate and Luke started to discuss their plans for permanently shutting down the criminals' operations, Mary meekly exited pointing out it was Bat Team stuff and she wasn't part of it.

Kate tells Mary she can't take part in her missions.

Later, when Kate was planning to infiltrate the Lookout, managed by infamous mobster Johnny Sabatino, to retrieve Lucius Fox's journal she helped her choose her outfit and even shown her the one she was planning to wear, however Kate told her she won't come with her as it was to dangerous and Julia would be her backup instead. As they left the room, Mary was left visibly saddened.

Mary talks Luke into letting her go save Kate and Julia.

After both Kate and Julia were captured, Mary was informed by Luke, who asked her to be his tech support while he would go to the club to rescue them, however she stated that it would have been better if she was the one who would have gone there, since Sabatino's cousin Aria owed her a favor for saving her life and because she trusted him to back her up better than she could for him.

Mary tricks Sabatino.

Having convinced Luke, Mary infiltrated the Lookout, passed by Reagan's counter asking her a vodka in order to gain strength, and then met with Aria asking her to brought her where her cousin was; once there she gave Sabatino a suitcase stating she was the heir of Hamilton Dynamics and wanted to take part to his auction to buy the Batsuit for $10,000,000.

Mary saves Batwoman.

Sabatino replied that she could have it after they killed the vigilante, then, taking advantage of a shortcut caused by Luke, Mary used Batman's laser saw to free Kate allowing her to defeat the mobsters and retrieve the journal while Mary was escorted to safety by Julia, who was freed as well thanks to her intervention.

Kate confesses to Mary that she always loved her like a real sister.

Later that night, after the mobsters were all arrested, Mary reunited with Kate outside. Kate asked Mary if she wanted gratitude or an apology first, to which Mary played it cool, saying Kate could choose. Kate admitted she always regarded Mary as her sister and, due to having already lost one, didn't want to lose her as well. Kate apologized for always sidelining Mary and promised not to anymore, welcoming her step-sister onto the Bat Team. Overjoyed, Mary simply hugged Kate.

Luke brings Mary to the Batcave for the first time.

Afterwards, Luke brought Mary to the Batcave for the first time and prevented her from taking a picture of it stating that that place must remain a secret, despite in doing so he accidentally revealed her that Bruce Wayne is Batman, leaving her speechless.[6]

Mary watches as Kate and Luke argue.

Kate discovered that Julia interrogated Reagan about the journal's location without informing her, so she began to question her loyalty and argued with Luke about it while Mary listened knowing that Luke was right that Kate shouldn't have let Reagan steal something so important.

Mary tries to talk Kate into apologize to Luke.

She watched as Luke left the room stating that he didn't want to be around Kate; she meekly suggested to her step-sister that searching for the item would be easier with Luke around.

Mary and Kate investigates Hush's kidnappings.

Then, while they were investigating the persons kidnapped by the mysterious "Hush", after hearing that the second victim was N.S.A. agent Tony Kim, she made the connection that the first victim, Professor John Carr, taught courses in cryptography at GU so whoever was kidnapping them was trying to decipher the journal.

Mary has trouble operating the Batcomputer.

Later that day, albeit Kate and Mary realize that they could use Carr's pacemaker to track him to his last position and discover where he was taken captive, neither of them had enough computer savvy to do the job. Right at that moment, Parker Torres's girlfriend Gina called Kate at her office and asked for her help as instructed by her girlfriend in case of danger since Parker has been kidnapped, which leaves Mary perplexed.

Mary gets jealous at Parker entering the Batcave.

After Parker was rescued and brought to the Batcave, Mary became immediately quite jealous of her and remarked how she was the last to learn her own sister's secret identity.

Mary and Parker bonds over eavesdropping on Kate's relationship status.

Though Mary would insult her, calling Parker a "random teen" and implying everyone is now allowed to enter the Batcave, she later bonded with Parker on eavesdropping on Kate's relationship status when Sophie came to Wayne Enterprises's office and spoke with Kate about her growing relationship with Julia.

Mary informs Kate about the secret of Lucius Fox's glasses.

That evening, while helping to upgrade the computers to find the previous locations of Professor Carr's pacemaker, Mary, Kate and Parker learned that he was in Arkham, leading Kate to preparing for an assault on the asylum. Meanwhile, looking around with curiosity through a box with Lucius' belonging, Mary found a pair of eyeglasses and discovered that wearing them she could read the code Lucius Fox used to write his journal, which she quickly informed Kate about right before she ran off to save Luke and Julia.[10]

Mary informs Kate about Tim Teslow.

The following day, after one of Arkham escapee, former tight end for the Gotham Goliaths turned criminal Tim "The Titan" Teslow, started a killing spree in Gotham managing to escape a first confrontation with both Jacob and Kate, Mary shown up at Wayne Enterprises informing her step-sister about him and prompting her to visit the criminal's brother Apollo. However Mary suggested Kate not to go interrogate him as Batwoman due to their father having declared war to the vigilante, insisting that he would never see Batwoman as one of the "good guys", despite Kate being sure she could made him change his mind.

Mary oversees Luke's attempts to destroy Kryptonite.

Worried due to Kate being out interrogating Apollo as Batwoman, Mary tried to distract herself by following Luke's attempt to destroy Kryptonite using acid and eventually asked him why not to use an hammer, then realizing how stupid it sound told him to ignore her since she was stressed and didn't control what she said.

The Bat Team investigates The Titan.

After Kate's second confrontation with The Titan, Mary reseted her shoulder and tried to convince her to avoid a rematch with him due to her body needing a few weeks to heal, but Kate replied that she didn't have that kind of time. Meanwhile, Luke found a connection in the people that The Titan is targeting due them having all had a role into covering his medical condition, which Mary confirmed just by looking briefly at The Titan's CTs.

Mary confronts her step-father about trusting Batwoman.

Later, Mary took the initiative and came up with a plan that drawn out the Crows using the Bat-Signal on a rooftop telling Jacob that she trusted Batwoman since she protect others without asking for a penny and in order to change the city's perception of the Crows he should work with someone to which the city really has hope to; the girl then watched as Jacob reluctantly accept a truce with Batwoman.

Mary and Luke watches the Titan's ambush at Gotham City Arena from the Batcave.

That night, during the ambush for The Titan at Gotham City Arena, Mary followed the operation with Luke at the Batcave and was informed by Julia to be careful since she and Sophie didn't believe in Jacob's change of heart, a suspicious which turned out to be true since Jacob ordered his men to gun down both The Titan and Batwoman, who luckily managed to escape.

Mary comforts Kate over their father's betrayal.

Later at Wayne Tower, Mary tried to comfort Kate about what happened with Jacob and they both agreed to feeling betrayed by him. Kate admitted to Mary that she naively hoped to come clean about being Batwoman to her father one day, breaking down in tears as she recounted the pain she felt at Jacob shooting her. Kate thanked Mary for having her back, to which Mary proposed a toast to sisterhood.

Kate tells Luke and Mary about the last piece of Kryptonite.

Luke then arrived, revealing that the Kryptonite had been reduced to dust thanks to Mary's "hammer" idea, prompting the latter to blow the dust off the table. Kate assured the two of them that from now on, there wouldn't be any more secrets between them. She revealed to Luke and Mary about the second shard of Kryptonite which Supergirl gave her during the Crisis, asking them to trust her with it until she can talk to Kara about what to do.[21]


"You're the one thing I did right."
Catherine Hamilton-Kane to Mary Hamilton[src]

Mary is very excitable, talkative, friendly, and kind of a social butterfly; she is described as her step-sister Kate Kane's polar opposite,[22] with one of Kate's trainers dubbing her as "Girl Who Talks Too Much".[3] Despite coming off as a ditzy socialite, Mary is a very kind-hearted individual who will go to any lengths to help those she loves and the people in need, such as Gotham's underserved communities.[7] Due to the bond she shares with her step-sister Kate, Mary is one of the few individuals who can talk her around.[11]

Because of their differences however, Mary and Kate were never really close, much to Mary's dismay, but she still tried hard to be friendly and supportive of her step-sister. As a result though, Mary harbored some resentment towards Kate for dismissing and only seeing her as a replacement for the latter's biological sister, Beth. Mary even lashed out at Luke Fox over how Kate still favored a serial killer to her despite all her best efforts to be a good sister[13] and began questioning Kate's love for their family after she refused to talk to Mary since she had "work to do" when their parents were about to divorce.[4] However, even when the two of them are at odds, Mary is extremely quick to forgive Kate.[9] When Kate finally confessed to having always loved Mary like a real sister and apologized for sidelining her in the past, Mary was so moved that she was unable to reply and simply embraced Kate.[6]

Mary is also quite empathetic and sensitive; she was horrified after discovering that her mother had manipulated the DNA test on Beth's alleged remains in order to gave Jacob and Kate closure,[13] having a very hard time forgiving Catherine for this deception. Mary felt great sorrow when her mother and step-father were about to divorce,[4] and devastated for being unable to reach and act more sisterly with Kate. Also, despite her animosity towards Alice, Mary came to befriend Earth-TUD14 Beth after realizing she was nothing like the former.[2] Mary further demonstrated these traits, as well as an impressive stoicism, when choosing not to leave her clinic during a bomb alert in order to stay with her patients who were too weak to be evacuated,[5] or when putting her own life in jeopardy in order to save her step-sister and Julia Pennyworth.[6]

Mary has proven to be quite an assertive, inquisitive, and free-spirited girl, not bothering about being politically correct when questioning Sophie Moore's sexuality[11] or discussing her past relationship with Kate and the impact it had on her.[7][14]

After her mother's death, Mary greatly matured, taking full charge of her step-father's trial to prove his innocence in Catherine's murder. In her grief however, Mary also became much more withdrawn, considering shutting down all of her social media accounts and even closing her free clinic, feeling she couldn't be a good doctor when she was unable to save her own mother.[9][15] However, Mary eventually managed to overcome her grief and decided to continue her path of being a doctor and influencer, keeping both her clinic[18] and social media accounts open.[1]

Powers and abilities

Former powers

  • Healing blood: After taking the universal cure-all Desert Rose as an antidote to Beth Kane's poison,[15] Mary's blood was able to heal allegedly every illness by transfusion.[18] The properties of the blood seemed to vanish after a while since, analyzing her own blood some months after taking the antidote, Mary found nothing abnormal anymore.[1]


  • Genius-level intellect/Great business acumen/Expert tactician/Leader: Mary has proven to be a very savvy, intelligent, and cunning individual. She is extremely skilled strategist and planner, having secretly run her own clinic without getting caught through siphoning funds from Gotham University.[3] Mary dealt with various patients on her own, not having any other staff members.[11] She was also very accurate at orchestrating her movements in order to cover her activities and real interest for medicine by posing as an irresponsible party girl,[7] even to her thousands of social media followers. Mary is also a fairly competent business planner, helping Kate Kane to open her gay bar, The Hold Up, and taking over its design.[4] She also demonstrated an extraordinary memory[8] and is an excellent tactician, taking charge of the organization of her step-father Jacob Kane's trial defense tactics[9] and developing a plan to lure the Crows onto a roof so Batwoman could propose to Jacob a truce.[21] Mary is so brilliant that she correctly deduced the existence of the multiverse, its collapse, and the birth of Earth-Prime after reading Beth Kane's astrophysics notes,[2] as well as involuntarily proposing an effective way to destroy Kryptonite.[21] Mary is regarded by Kate as one of the three most intelligent individuals she knew in Gotham, alongside Luke Fox and Beth.[18] She was the first person to correctly deduce Kate's identity as Batwoman on her own.[1]
    • Expert of deception: Mary is proven to be extremely skilled in the art of deception, using acting and improvisation skills to make up several stories in mere seconds in order to try and pass a checkpoint.[18] Mary also managed to trick Johnny Sabatino and several Gotham's mobsters into believing that she was at the Lookout to take part to their auction, allowing her to save Batwoman.[6]
    • Skilled investigator: Mary is very inquisitive and a capable investigator, having extorted information on Alice's plan from Dodgson while he was drugged.[12] She was also quite helpful in investigating the identity of Beth's doppelgänger when she first appeared.[2] Mary was able to figure out that Kate is Batwoman after connecting a series of clues[1] and helped Kate in figuring out Hush's kidnapping pattern.[10]
    • Medical knowledge: Although Mary is just a medical student and has not yet achieved her M.D., she has a tremendous amount of medical knowledge, enough to operate her own illegal clinic[3] and identify the exact extension of a patient's brain damage just by looking briefly at a CT.[21] Her medical skills seems to be even greater and more accurate than that of many paramedics[7] and she was able to perform various surgical feats, such as extracting a car hood out of a man's abdomen and help him recover within a night.[15] Mary also displayed a great knowledge of injuries caused by various types of bullets, able to deduce in less than an hour how to better treat the wounds they made without using specific equipment.[14]
  • Skilled hand-to-hand combatant: Mary is proven to be a moderately skilled unarmed combatant, capable of holding her own in a fight against Alice when the latter was severely weakened by her headaches and eventually overpowering her.[18]
    • Skilled knife-wielder/Knife thrower: Drawing from her knowledge on the human anatomy, Mary has incredible aim with knives; despite her fear, she was able to stab Dodgson in the leg with remarkable accuracy, debilitating his ability to move.[11]
    • Skilled markswoman: Mary knows how to use a gun thanks to training from her step-family.[11]
  • Indomitable will: A driven and determined individual, Mary is nearly fearless and almost never gives up in most situations. For example, she chose to stay behind and help her patients during the evacuation of Bennett Ave. after a bomb alarm, despite knowing full well that no one knew of her clinic's existence and thus the authorities wouldn't care to evacuate it before detonating the bomb.[5]
  • Network: As a member of the social elite and influencer-in-the-making, Mary has a wide array of contacts,[7] including various connections between the poor Gothamite communities she helped.[11] In Bennett Ave., Mary has a reputation of "knowing everyone".[5]


  • Gun: Mary carries a gun so that she can protect herself after nearly being killed by Dodgson.[11]
  • Laser saw: A device which can cut through any substance. Mary used it to save Batwoman after she was caught by Johnny Sabatino.[6]




Promotional images


Season 1


  • Mary loves to watch puppy videos on YouTube.[11]
  • She's a huge fan of Glam Jams.[7]
  • Mary had over 3.5 million social media followers,[4] but lost most of them after the revelation of her mother and step-father's underhanded activities.[8]
  • Mary's blood type is B-negative.[1]
  • Even though Mary and Beth aren't recognized by law as step-sisters, the two have referred to each other as such.[15]
  • Mary is the first character outside of any team of heroes to have correctly guessed the multiverse's existence on her own, although then dismissing it as a "mere speculation".[2]
    • She is also the first Batwoman main cast character to discover Kate's identity on her own; Beth discovered it by looking into her eyes when Batwoman saved her from drowning while Sophie suspected it until she was convinced of the contrary.
  • It's possible that Mary isn't Jewish like the Kane family as her mother was not and traditionally, all Jewish descent through the maternal line.

Behind the scenes

  • In the DC Comics, Mary Elizabeth "Bette" Kane is the original Bat-Girl, who served as Batwoman's sidekick and Robin's counterpart. Growing up, she would adopt the alias Flamebird (later Hawkfire in The New 52) in response to her counterpart's development as Nightwing. Also in the comics, Mary is Kate Kane's younger cousin instead of her step-sister.
    • In Batwoman, it's unclear who Mary's father is. Similarly in the comics, the identity of Mary's parents was a narrative mystery, especially in The New 52; despite being presented as Kate's cousin, Mary isn't the daughter of any of the known Kane siblings: Nathan (childless), Philip (unmarried), Martha (mother of Bruce Wayne), and Jacob (father of Kate and Beth Kane).
  • The character's name is likely a nod to a well-known sixteenth-century ballad from Scotland based on an apparently fictional incident about a lady-in-waiting to a Queen of Scotland.


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