She's 42. He's 90. The New York Daily News has the details.
I'm sure all of Sumner's children (who have all at one time or another had public tiffs with their own pops) are rolling their eyes.
From the article...
Viacom spokesman Carl Folta also assures us that “Mr. Redstone doesn’t have any involvement with this child,” though a source close to the May-December pair, who were born nearly half a century apart, says the little girl is named Alexandra Red, which was shortened from Redstone. “They cut the last name on purpose so the media doesn’t find out,” says a source close to the pair. “They are not telling anyone.”
Good luck, kid.