User blog comment:Xandermcc/More Arrowverse PSA's?/@comment-24695878-20170216205520/@comment-27700324-20170217170938

She has had some of her own villains on the show. The Dollmaker AKA Winn is a main cast member. Bizzaro #2 is a Supergirl foe. Silver Banshee is a Supergirl villain. Reactron became Supergirl's villain as of the new krypton story. Cyborg Superman is now a Supergirl villain as of Rebirth. So yeah there are only a couple of her own foes left that i didn't list and they probably want to save those for S3.