guys or girls?
for any two people:
watch movies
tell funny/ scary (real or fake)
tell jokes
truth or dare (don't be boring with it. i choose dare every time to make things interesting)
tv
make up a game
this would be easier if there was a specific gender in the question
Chat with our AI personalities
A simple sleepover or Paintball
You could always just leave them alone and let them have their own fun or offer them some things that interest the both of them to do together that way everyone has fun!
stardoll.com
hmm... 11 ..ok well try and get a theme... like chocolate spa...things like that. Also lloking up games online is good. i found some. http://www.party411.com/gameguide-sleepovers.html
Here are a few suggestions: Day trip out to the cinema or ice skating rink. You drop them off and pick them up. Then on the night a sleepover with a chocolate fountain and leave them too it. There teenage girls so its more of getting in groups and gossiping and manicures and pedicures! They dont want to be cramped by there parrents anymore. Adding to this, maybe set the sleepover as a themed party? Hawaiin, murder mystery etc.