I need to get away from one of my really good friends...?

shes a terrible unfluence on me,and my mom dad and nani think i should drift away from her.but i dont know how. if i dont do something for her, she 'hates me forever' she hates so many people,and shes just a huge bully. if i dont hang out with her,she talks about me and is really mean. what should i do?!