Leighton Meester, Adam Brody Welcome Daughter Arlo Day; 'Gossip Girl' Excited Over Celeb Babies' Playdates with Blake Lively's Daughter

Former "Gossip Girl" star Leighton Meester and former "The O.C." star Adam Brody are now the new parents of a baby girl. People Magazine confirmed that the 29-year-old actress gave birth last Aug. 4, and she and Adam have named their first child Arlo Day.

Leighton and Adam married in secret in 2014. Just like their wedding, the couple have never confirmed that they were in fact in the family way, according to Us Weekly. But fans have spotted the actress with her baby bump back in July, as she spent a day out with her girlfriends, according to E! Online.

People only got wind of Leighton's pregnancy when she hinted this on Nylon Magazine, "Most people I know are starting to get married. It'll be kids next. I like the grown-up stuff. I like having a house. I've got dogs. I started [Gossip Girl] when I was so young. And once it was over, I wanted to do things that were exciting and challenging and more me—more my adult taste.'

Since being married, Leighton admitted that her priorities have indeed changed. "'My values have shifted greatly in terms of what I find important. It's my family, my friends and having a personal life. Those are the things that need nurturing," the actress said via InStyle.

Leighton and Adam met while working on the film "The Oranges" in 2011, but only started dating in 2013, according to another Us Weekly report.

Meanwhile, as news of the baby's birth came, fans of "Gossip Girl" have been more than excited. Many avid followers of The CW show are already planning playdates, tea parties and birthday parties for Leighton's daughter, Arlo, and her "Gossip Girl" co-star Blake Lively's daughter, James. Blake's baby with Ryan actor Reynolds is a few months older.

Fans took to Twitter to express their delight with the baby news, while others are predicting a "Gossip Girl" follow-up.

Blake Lively and Leighton Meester both had babies within a year so they're children can be bestfriends just like S & B were

— rica (@ericahart7) September 24, 2015

So Leighton and Blake both have baby girls.....16 years til Gossip Girl 2.0?

— Bourbon N Bays (@BourbonNbays) September 24, 2015

Leighton and Blake both had baby girls this year... Here comes Gossip Girl Next Generation (:

— Raquel Cashmore (@RaquelCashmore) September 24, 2015

It's cute how Blake and Leighton both have baby girls but they gave them boy names

— Allison (@swiftiemeester) September 24, 2015

But another Twitter user reminded everyone of the rivalry between the two, as it was with their characters on the TV show.

Leighton Meester named her baby Arlo Day so I think she beats Blake Lively in the weird baby name category

— Kristen (@kristytipsen) September 24, 2015