I am a preteen and have a list for you!
I don't know if they are a boy or girl but if they are a girl
Bella Sara
Barbie Girls
Brit Chicks
Zwinky Cuties
Go Supermodel
Stardoll
And here are some for everyone
Free Realms
Pet Pet Park
Neopets
Club Penguin
Pixie Hollow
Pirates of the Caribbean Online
Minyanland
Tootsville
Fantage
Panfu
Wiglington & Wenks
Habbo
Dizzywood
Secret Builders
Whyville
Moshi Monsters
McWorld
BuildabearVille
Webkinz
Shining Stars
Ty
Trollz
Chobots
Boombang
Planet Cazmo
Kung Fu Panda World
Vizvoz
Franktown Rocks
Taatu
Woogi World
I don't know if they are a boy or girl but if they are a girl
Bella Sara
Barbie Girls
Brit Chicks
Zwinky Cuties
Go Supermodel
Stardoll
And here are some for everyone
Free Realms
Pet Pet Park
Neopets
Club Penguin
Pixie Hollow
Pirates of the Caribbean Online
Minyanland
Tootsville
Fantage
Panfu
Wiglington & Wenks
Habbo
Dizzywood
Secret Builders
Whyville
Moshi Monsters
McWorld
BuildabearVille
Webkinz
Shining Stars
Ty
Trollz
Chobots
Boombang
Planet Cazmo
Kung Fu Panda World
Vizvoz
Franktown Rocks
Taatu
Woogi World