My cousins just went through this. As far as any of us could tell, the state seemed to be mostly looking at whether or not there were reasonable sleeping arrangements and such. The cousin in question is only an OK housekeeper and already had 4 boys under the age of 10 so there is no way to keep it spotless.
Her older children also had to speak with the woman from Social Services. The 10 year old told us they had asked him questions about how he would feel about having a new child in the house and such.
I hope all of this works out for you.