Thanks to bossip.com for the story of Catherine Cook, who with her brothers, just sold their start-up for $100 million to the publicly traded Latino social networking site Quepasa. It’s still pretty unusual to find girls/women making these gigantic deals–especially so young.

Catherine and her brother Dave started myYearbook.com when they were 15 & 16 years old. Within 6 years they had 20 million mostly teenage users–interactive yearbook pages, games, contests. Big brother Geoff helped some–already successful in new media, he spotted them the start up cash  and sat  in the executive suite while they went to college.  

But Catherine is the acknowledged developer-genius of the group. Sometimes described as the female Mark Zuckerberg, at 16 she led a staff of 12 developers. MyYearbook is the third largest social networking site, after Facebook and MySpace.

 Now 21, she is a student at Georgetown University and will continue to manage the development part of the newly combined company, while brother Geoff takes over as COO of Quepasa. The trio got $82 million in Quepasa stock, $18 million in cash.

The Cooks, from New Jersey, with the company based in tiny New Hope, PA, now look globally. Quepasa is huge in South America. The combined revenue of the two compnies: $33.6 million…2.4 billion page views.

Not bad for a college student in these hard economic times, especially a girl.