Gaydar: Second Opinion?

There is this girl, mind you we're in high school, and she's been really nice and I had assumed she was straight since she has dated guys in the past (Soberly?), but anyway she's made it a point to talk to me, but I sort of wrote it off as her just being amiable. Anyway she's an artist and I know some of her friends are into punk stuff, but when she cut her hair really short it sort of threw me through a loop. Anyway we got talking about music and movies in class one day and she asked me if I like Tegan and Sara and I said yeah and some other stupid thing about how Canadian indie doesn't sound like American indie and then the class after that she found out I wasn't going to prom and she told me she wasnt going to prom (even though she won queens court last year and could have any date she wanted and $ isn't a factor) and we walked out of class together and got talking about this volunteering thing I do and she gave me a literal pat on the back... So I'm just kind of wonder if you guys think she's interested or just a friendly, straight girl with short hair, an interest in distinctly lesbian music, and who is electing not to go to prom for whatever reason.