I dont have kids but a straight NO would be wrong IMHO. Talk to the parents. You will know right away if the answer is yes or no.
My secretary had "mixed company" sleepovers about once a month for about 8-10 kids. She is very proper, no sex, no drugs, no booze. She has a huge house. The kids were up until about 2 watching movies, playing pool and hanging out in the basement with the doors open (or outside around the firepit) and parents on premises. Then the boys were on one floor, the girls on another and one/two sets of parents (light sleepers) in between.