Slumber party with her best friends. That's always memorable.
I think setting up a small stage & having everyone perform a talent, or karaoke or even musical instruments if you have them. That would be fun. Theyll pretty much entertain themselves after about 2 hours tops. OR, you could call on your friends & do a show for the guests. Have fun.
Make plans that include social network connections, and even letting them make a "Second Like" charactor. Really at that age the social media and texting is all they want to do.