Cps and filthy house?

Hello everyone, first time here wanted to know how this family situation is going to play out. My sister and her husband have 3 little girls. Well her husband decided to have his cousin and her boyfriend stay with them along with their 4 kids. So that is 11 people in Total they live in affordable housing and these additional people were never put on their lease. Both my sister and her husband have issues with cleaning the apartments gets unbarealy filthy with just them and as to my understand non of them were cleaning at all. Anyways cps ended up coming because the guests actually had been hiding from cps for 5 months and I believe someone had found out their address and reported them. My nieces were not at the house at that time because they went on a trip with my sister. The other 4 children were removed and photos were taken of the whole house. Cps asked her husband where his kids were and after he explained they said they would be back Tuesday (today) are they going to remove my nieces too? Also are they at risk of being evicted, is HUD notified about police and cps visits. My only concern is for my nieces. They aren't taking the situation seriously and claim because they were called for the house guests they ae not at risk as long as they clean the home up. This however is the second time cps has seen the home in this sort of condition. Just looking for advice and insight.. I apologize if this is a mess my mind is racing because of all of this.