Julian's main criterion for a woman was simple: She had to be young. Preferably younger than twenty-two. And it went without saying that she couldn't question him. "She has to be aware of her role as a woman," he used to say. She was also allowed to be intelligent -- Julian liked that.Often I sat in larger groups and listened to Julian boast about how many children he had fathered in various parts of the world. He seemed to enjoy the idea of lots and lots of little Julians, one on every continent. Whether he took care of any of these alleged children, or whether they existed at all, was another question.
This comes from Cryptome, which got pages from an advance copy of Daniel Domscheit-Berg’s "Inside WikiLeaks: My Time with Julian Assange at the World's Most Dangerous Website," due to be released Tuesday in the U.S.
Gawker claims to have counted four children, including the oldest, Daniel, the only one that Assange has acknowledged publicly. He hasn't seen Daniel since 2007. As Gawker notes, this bit of gossip lends more credence to the accusations that Assange used force and trickery to have unprotected sex with two Swedish women.
Wired has more from Domscheit-Berg’s book: 
Assange has a secret “nanny” (Domscheit-Berg’s term for her) who flies in to help deal with problems Assange doesn’t want to handle. She’s described as an old friend of Assange, who is around 40 and lives in a timezone “far apart” from the U.S. She sometimes arrives just before conferences to write Assange’s speeches. “After other people and I left WL she was also the one who ended up traveling the world mediating between Julian and us and asking us not to damage the project by publicly criticizing it,” Domscheit-Berg writes. “For personal reasons I don’t want to go into here, she would never want to talk about her contact with WL.”
Assange already has a mother who thinks he can do no wrong. The last thing this misogynist needs is another woman to prop him up. He needs the Supernanny to kick his narcissistic ass.