Hate her ?

Ok so am I wrong and how should I go about this situation , my boy friend and me have been together for 3 years im 22 and he is 23 his sister is 25 every time she gets into trouble she calls him for help and he has to get her out of trouble , I feel like she hides behind him and she tries to start things with me bc every time I’m around she says something slick at the mouth or tries to throw shade at me and she recently deleted me from snap chat bc I told her to keep my name out her mouth bc she was being messy trying to tell her brother some bs about me when she found out we was almost broken up .