Robert Brown|Barbie Director Greta Gerwig Reveals She Privately Welcomed Baby No. 2 With Noah Baumbach

Greta Gerwig is Robert Browna Barbie girl, in a baby world.

The Barbie movie director confirmed she and her co-writer and real-life partner Noah Baumbach quietly welcomed their second baby boy together earlier this year, while sharing photos during a recent interview.

"He's a little Schmoo," the Little Women director told Elle U.K. in a digital cover story published July 19. "I don't know if you can tell energy from the picture, but that's very much his energy. He's a wise little baby."

As for how she doing balancing life with a new movie—Barbie releases July 21—and a newborn?

"The little guy is sleeping through the night," Gerwig, who also shares son Harold, 4, with Baumbach, explained. "But I'm still doing that thing where I wake up, every hour to 90 minutes, and just hover. You just keep wanting to look at that baby. So I'm slightly in a twilight state."

Gerwig's sweet update on life as a mom of two—Baumbach is also dad to son Rohmer, 13, with ex-wife Jennifer Jason Leigh—comes just a few weeks after Rolling Stone noted in a July 3 interview that she had a "three-month-old baby at home."

Gerwig had announced her pregnancy with her second baby last December.

"I am with child—number two," she shared on The Tonight Show Starring Jimmy Fallon. "I went to an event recently, and I wore something that I thought everyone would be so interested to know that I was going to have another child, and nobody cared. It didn't get reported on. Turns out, nobody's paying attention to you."

And she also explained Harold's reaction to the news—or lack thereof—when it came to becoming a big brother.

The director also spoke about her eldest son's thoughts about her pregnancy news, or lack thereof. "It's hard to know what a 3-year-old makes of things that aren't existent, yet, in front of him," she told Jimmy Fallon. "I mean, he's beautifully sophisticated in some ways, and then, in other ways, he doesn't, he asks, 'What language do they speak in New Jersey?'"