My Friend is Causing Problems @ Slumber Party?

Whenever me and my friend have a sleepover she always wants to stay up until 5 in the morning. I like my sleep and go to bed at around 1 or maybe 2 at a sleepover, but noooooo, she has to go to bed at 5 and wake up at 6 or 7????? WTF? When I tell her that I want to go to bed she gets all POed and doesn't talk to me. She'll start whining and pinching me if I try to go to sleep. Grrr... Is there any way I can get her to stop this? (Besides drugs/sleeping pills in her drink) (We're only 12!)