Mean girl won't leave me and my friends alone... Please Help!?

She definitely just wants attention. Keep doing what you're doing, ignore her. Eventually she'll realize that your better than that and you won't stoop down to her level. Thats all she wants. She wants to bring you down to her level, then she'll beat you with experience (got that off a shirt). If you want, you can say something, just say "You know, I wish you hadn't said that." or "I wish you hadn't done that." That should get her thinking and maybe she'll realize that all she's gonna get out of you are those responses. Who knows, maybe she'll change after that and realize that she can't make her own life better by making other people's lives worse. Try this, if it doesn't work you can try something else, but I'm sure it will.