Describing her as the “It Girl,” NBC’s “Today” show had on the daughter of “NBC Nightly News” anchor Brian Williams this morning. Allison Williams is one of the stars of “Girls” which debuts on HBO Sunday night.

In a chat with Ann Curry and Carl Quintanilla, Williams describes the show as “an accurate depiction what it’s like to be in your early 20′s in New York.”

As for the “adult themes” of the HBO show, Williams says mom and dad are cool with it. “They lived through the filming of it with me and every time I’d read a new script I’d come home so excited. And I think they’re very proud.”

Watch, after the jump…