I have issues with my bfs little sister shes about to be 11 and basically flat out expresses that she doesn’t like me, maybe not verbally but physically.. from the dirty looks to the eye rolls.

Her and her brother have always been close even before I knew him, Ive been with him for two years now and nothing has changed. Im always nice to her, im always trying to do stuff with her, but nothing helps, she gives me this attitude, she doesnt listen to me at all when I watch her at all, then I talk to my bf about it and he basically says like “oh well she never does that, shes not like that” and shes just off the hook.. I know I probably sound immature but I cant take her pushing her way between us and basically saying im being mean, when Im telling you I definitely am not, I correct her when she does stuff that isnt nice or respectful, whereas her mom, brothers and dad dont ever tell her when shes in the wrong, or tell her no.. I cant talk to my bf about it bc he says im being a “dick” or to “shut the fuck up” bc his sister “isnt” like how I describe.. but she doesnt do the things she does to me around him..it doesnt matter what she does, what she says, shes always innocent in his eyes, and she talks like shes 5 and still says “potty” she won’t do anything on her own and basically has my bf do everything for her.. I just feel like living here with his family, him being 31, is just claustrophobic and I try to push him to get a place with me, hes a roofer and makes good money, I work too.. it might just be retail but I still work. I dont know what to do, I cant talk to him, I feel sad around him, and I just feel defeated with the whole sister situation..