Kate Kane

Kate Kane is a Gotham City socialite and the cousin of Bruce Wayne. She is currently engaged to Maggie.

Biography
At some point, Kate Kane learned from her cousin, Bruce Wayne, the importance of keeping up appearances.

Later on, Kate became engaged to Maggie.

Kate invited Bruce to her and Maggie's "engagement thing", and later left him a voicemail to remind him of the event, implying that it meant a lot to her for him to come.

Trivia

 * In the comics, Kate Kane is Bruce Wayne's maternal cousin and the vigilante Batwoman.