Stardoll, a social site that helps young girls create paper dolls of celebrities, has landed a $6 million investment from Sequoia. Unlike most Silicon Valley investments, Stardoll (formerly Paperdoll Heaven) isn’t a cutting-edge Web 2.0 startup - it’s a simple social network that enables 7 to 17 year old girls to create, share and discuss paper dolls. Surprisingly, the site has been a big hit - it attracts 1.2 million unique visitors a week from over 200 countries. Stardoll makes money by charging for “Superstar” membership - this costs $2.85 per month and gives users access to exclusive dolls.