Its something they're keeping from the comics
or at least I presume she's a lesbian, I've just read that she's romantically connected to a female in the comics & the show is keeping that. I like that they're doing that as I feel you don't always get that. Sure some comic book characters are only now being discovered as LGBT as they couldn't be written that way at first or maybe they're being changed, but I still don't feel that when the characters are adapted to screen you always get the sexuality. Or maybe I'm just watching the wrong things