How do I get this ***** to leave?

I'm done playing nice with this guly girl at school who stalks me, talks smack about me, and won't leave my group even though we've all told her to leave. I'm so ready to fight her right now jsut thinking about it! What the hell do i friggin do? This girl is a tiny persian Taylor Swift wannabe and I need to know how to burn her bad enough so she leaves. And maybe cries.