I haven't read the thread but I'll just say a few things. She isn't sounding serious, at least not yet. She may have a good interest in you, but don't fall in love. Keep yourself on the ground and don't let her cute gestures take you places. Chances are they're close because he secrety wants to date her or have dated before. IE. Unecessary thinking and trust issues on your part. Gotta introduce yourself into her life slowly but not so slow she's waiting for you. The complexities

Not saying I'm a mad pimp yo

but it really takes intelligence and interest to hook a girl worth your time.
EDIT: HOLY GOD RUN FROM THIS GIRL. anyways..
I'm currently getting re-involved into the mix, and she's looking to be the right kind of girl.