My mom is a violin teacher and will give private lessons to a girl I hate.?

And my mom teaches at our house. I don't want this girl in our house, looking at pictures of me on the wall and everything and then seeing what a tiny place we live in. She is mean enough without knowing all that information. I know that we need the money, but I can't help but disapprove of this girl coming to our house. Am I being selfish?