She's too old for Club Penguin, too young for Facebook.
So where's your tween spending her online time? Girls this age have sites all their own.

The Site:  Beacon street girls Contains games, a journal and talk based on squeaky-clean girls from the books.
On boys and bodies: Stresses staying healthy, playing sports, and getting positive attention (i.e., for smarts, not short skirts).
Parental controls: A parent's e-mail address is required for sign-up; parents can cancel at any time.
The Site: Girls life  The online home of the tween magazine and a past Parents choice award winner.
On boys and bodies: "Love" talk doesn't stray far from "liking" and hand-holding. A section on periods lets her ask questions.
Parental controls: Kids under 13 need permission to join. Adult moderators have a strong presence, even offering crush advice when asked.
The site: The online home of Tampax, created especially for tween and teen girls.
It features lots of advice on puberty, menstruation, her changing body and lots of great fashion tips.
The site features lots of fun games just for girls. There are cooking games, dress up games, celebrity games, makeover games and pet games.