I think currently, your house is alrdy consider VERY crowded alrdy. I cant imagine staying in a 5rm flat with the other 8 ppl and my hub still wanna let more ppl to move in. Well, since your hub will listen to you if you insist not letting his relatives to move in, then shdnt be a pro. dont care about what others say. It is alrdy very good to let your sister In law move in with your. Your house is not a charity organisation.