Sain wedi'i Rhannu

so I have a friend who i don't really like but anyway she has a friend and she is so rude and disrespectful and she gave on my friend a really bad impact like now she hits us hard and when we dont wanna do something she forces us into it but before she was the opposite amd idk what to do i've been trying to tell her she just says she changed like no she didnt anyway zee out