I'm just going to second everything you've said here. Maybe I'm also biased and bitter, because I've tried to point out to her the error of her ways also, but I definitely can't say she's gotten better. Probably worse, but I mostly ignore her now. She has a real superiority complex and I think she really doesn't see that anything she does is wrong. She's always more 'professional' or 'mature' or whatever it is she's describing herself as these days.

Also she is better than you because she goes to some fancy high school with all the AP courses. All of them. At least, this is the impression I've gotten from her.