Help my sister in laws are driving me nuts!

Ok I have 4 sister in laws, one who I love so much. The one tjhat I get along great with is my brothers wife. My husband' s sisters I can not stand!!!! We live in the same home so it is pretty hard to avoid them. First lets start with Percila she is ok I mean she is not the greatest person in the world but she helps out with bills and I could deal with her. Then there is Brandy, she is a diffrent story. She is 21 has had only two jobs and did not last more than a week at one. Her boyfriend left her at 7 months preg. so she just moved in and she is so lazy. Then there is Marissa who is 14 she probablty the worst of all. She decided to open her legs and got preg. she also lives there with her scumbag husband who is 17 and does not do anything as weell. They just sit around and smoke pot all day!!! I hate this kind of life style!!! I wish I could kick them out and avoid them. Not to mention that as soon as they moved in we started to get little roaches because they could nto pick up after themselfs. I was not raised like those low lifes adn I just find it so difficult to deal with them. I get home from school or work and try to get on my computer to do homework and they are already on their doing nothing!!! (Myspace, Youtube) (by the way I purchased the computer) What do I do?