Wtf should I do about this girl?

Okk. So at school, there's this girl that really dislikes me for some reason. I've never talked to her before, and she's always glaring at me and stuff. To be honest though, I don't really give a flying f*ck whether she likes me or not. The thing is, I'm good friends with a couple of her good friends, and whenever I'm talking to one of them, she just rudely s in, and starts talking to them, like RIGHT in the middle of our conversation. I'm quite sure that she's doing this purposefully too, because it happens quite frequently. It's starting to realllly piss me off. And I'm not going to confront her, because she just denies it. So, what should I do. Oh, and we're 16, btw.