It was recently shown on Supergirl.TV that a new character would be introduced in an episode of Supergirl. This character has some details that are confirmed and some that are not.
Hayley Sales has been cast in the role.
She will appear in the episode "Distant Sun"
The character's name is Emily.
She will be a rival for Maggie and Alex's relationship.
She is a member of the Bat family.
Now i know what you guys are probably thinking. This probably is just rumors. Plus the character's name is Emily. However the synopsis is down in the list of episodes and tells a different story.
Also other skeptics are saying that this character's name is Emily and not Kate Kane. Well i am here to tell them that J'onn J'onzz is also not called Hank in the comics yet in the show he is. So how did Kate earn the name of Emily? Well just like Bruce Wayne, Kate is rich. She has tons of money at her disposal and can become someone else if she wants to. My theory is that potentially Kate is in the identity of Emily to remain unnoticed in National City. For what reason i don't know. The show would probably come up with a better reason for her disquise. Maybe it is involved with Batman in some way?
Put your opinion on my theory down in the comments.