***** in my class bitching about me..help?

theres a slut in my class who thinks shes the most beautiful al alive and stuff..she and i have competition academically..i know she considers me a threat...the point is of late i came to know from few people in my class that she is bitching about me all the time..and she created really nasty things about me which are completely unreal..she tarnished my name before my friends..she tries to pickup fights no matter how hard i try to avoid..i just dont understand how to dal with these kind of bitches who use guys for gifts,,bills,,money,,timepass and who talks ill about people with 0% truth in it