How 2 fight against this gurl?

theres this gurl wants 2 fight me cuz i was fighting with her friend her friend called me a ***** and all these nasty names and i was just protecting myself but now she like wants 2 kill me and stuff, shes shorter than me, scrawny, and "tough" but my arms r scrawny and idk how 2 protect myself, she knows where a live and ive tried 2 talk her out of it but she doesnt want 2 listen, ive talked 2 adults and all they said was 2 fight back if necessary