rules for children sharing a bedroom in MI?

I am trying to find the rules for michigan, on the sharing of bedrooms for children. There are 4 children total.. 3 girls and 1 boy. Girls- 13, 10, 5 Boy-2 years old. A friend of mine is trying to get custidy of the 13, and 10 year old girls. CPS will be coming to the house this week to investigate the living situation of the house. she currently lives in a 2 bedroom home, very nice, and large. but again, only a 2 bedroom. She has no problem moving, to be able to get the girls. But we have looked online to be able to find something that states how many bedrooms that she is going to need, to be considered, good enough space. Or is there even a problem with the boy in the room considering that he is only 2 years old.

anything that you have, or experience that you have had... or a link, because we can not find it, would be helpful.

only serious answer please. these 2 girls are not being protected by there birthmother, and CPS has already removed them from her house. We just need to know what the rules are before they come over, so we can already have a plan in place. THANKS