I posted on here a few months ago asking similar questions for my DD's 8th bday party. In the end, she had 3 girls sleep over and it was perfect. They arrived at 6pm, did a craft, ate dinner, had cake, watched 2 movies, and played. They fell asleep around 12am and were up by 5am

, but they stayed down in the basement and were really well-behaved. DCUM told me to have pick up be after 10am but I am glad I stuck to my guns and had them picked up at 9am b/c by then they had been up for 4 hours and I wanted my house back.