I, since my daughter was 8... had sleep overs for her. At our home.
It was... only her close friends.... and thus kids that I know well and know their parents, well. VERY, well.
So, it was no problem.
I let my daughter.... decide... who to invite and how many.
She kept it to about 5 girls.
She did not want to invite a whole bunch of girls.
Only her close friends.
And I know their parents, VERY well.
The girls came over at the designated time.
I instructed the parents to make sure they are BATHED before hand. Before coming over.
We had food and the girls just had their own activities they wanted to do... it was fine.
They went to bed, late.
Like midnight.
I knew they would.
It was fine.
Its a sleep over.
The Moms were fine with that.
The next morning they woke up.
I made breakfast that my daughter chose and which she KNEW her friends, would like.
1 girl had nut allergies. So I took note of that and planned food appropriately.
They were all very self-reliant. No issues.
IF the girls wanted to, I let them call their parents ANY time.. .and told them to wake me up at ANY time, if they needed me. Even if it is 2:00am. They can wake me.
I slept on a sofa... nearby... but far enough for their privacy and I could hear them. I didn't get sleep either, because I kept my ears open for them. And I also checked up on them, during the night.
I also gave, each one of them flashlights to keep near them. I also had throughout the house, night-lights everywhere.
Personally, I would not, invite an entire class of kids, for a sleep-over.
And, if my daughter were invited to a sleep-over, to a child's party/home that I did NOT know, nor know their parents... I would not, let her go.
My daughter has gone to sleep-overs... a couple times. But it was to her GOOD friend's home.. in which I KNOW the parents, very well.
Just as an aside: a woman told me that her 12 year old niece, went to a sleep over once. At night, there were other adults there. They didn't know that. The parents were not told. Then during the night, as the girls slept in a side room... one of the men... went up to her and started touching her.
Yep.
You never know... what happens at a sleep over, or who will be there, or what the other adults are doing... or what the level of SUPERVISION is... at the sleep over. UNLESS... you know the child and the family/parents... very well.
AND you call them, anytime and they welcome that.
I would, NEVER let a 6-7 year old, go to a sleep over.