Anyone who saw the film The Social Network would have no way of knowing that Facebook founder Mark Zuckerberg has a sister. But now Randi Zuckerberg is generating headlines of her own - after six years working faithfully in her younger brother's shadow as Facebook's director of market development, she is jumping ship to set up an independent social media company.
The tech bloggers of Silicon Valley are rubbing their hands at the prospect of some sibling rivalry to follow on from the multiple lawsuits that the younger Zuckerberg - he's 27, she's 29 - has endured over the parentage of his wildly popular website.
More perplexed tech watchers wonder what Randi hopes to achieve that she hasn't in one of the world's most rapidly expanding companies.
She appears to have decided to have fun with her money and her instantly recognisable last name to branch out on her own, without doing anything to damage the Facebook brand.
"I'm proud of what I've done here… but I know I'll be able to do just as much, or more, for Facebook once I'm on the outside," she wrote in her resignation letter. She said her goal was "to launch my own innovative programming and work with media firms," adding: "Facebook will clearly be a central element in all my projects."