She's mad at her bf/ teasing you. Yeah, what they said, it's up to you to spin it. Don't care so much if the girl likes you back, because women generally don't. You have to give it a few dates or whatever.
What's going on: her bf is being gay and ditching her to go drink with her brother. Beyond weird. What's even weirder is that she doesn't have a ride home. So, that's why she approached you. She doesn't think *you're* anything special. A lot of guys think that the female world revolves around them, in the same way that women all think they're hot. Be objective about the situation: what's going on with *this* person?
What you could have done was gotten burgers and malted milk shakes with her or something, complained with her about the men in her life, talk about the types of guys you hate, and given her a ride back. Then dropped her your number, because it was a lot of fun just hanging out with her, and we should do it again sometime!
It sounds feminine, but women always fall for this type of guy.