Should I be getting annoyed at this?

So my boyfriend lives with his brother in a flat and his brothers girlfriend is really annoying me she is always around and she stays about 4 times a week they let her stay in the flat when both of them are going to work she cooks them dinner and cleans and all that. I only get to stay about 1 time a week and I just feel as if my boyfriend prefers his brothers girlfriends company to mine I feel as if I'm irrelevant and like I'm the unwanted one out of them all. I also woke with my boyfriends brother and girlfriend. Am I over reacting? I just feel as if she is so judgemental and she tells me what I can and can't do in my relationship 😡😡