In 1977, Mary Anne unknowingly met her future son, John Constantine, in her pub in Liverpool. After he got into a fight with her husband, Tommy Constantine, Mary Anne angrily kicked John out of her pub, proclaiming that she never wanted to see him again.
At some point, Mary Anne and Tommy had a daughter together. On 10 May 1982, Mary gave birth to the couple's second child, John. Unfortunately, she died in the middle of childbirth.
Due to Mary Anne's death, Tommy developed a deep, irrational resentment towards their son, John, blaming him for "killing" her.
Zed Martin came into contact with Mary Anne's spirit while in a coma. After their encounter, she was able to assure John that Mary Anne did not blame her son for her death.