Baby B! Leighton Meester, Adam Brody welcome their first child — a baby girl

Queen B has a new heir! Leighton Meester has given birth to a baby girl that we’re hoping will sport an enviable headband collection reminiscent of mom’s TV alter ego.

The “Gossip Girl” alum and her husband, Adam Brody of “The O.C.” fame, welcomed their first child earlier this month, according to reports out Thursday.

The ultra-private couple did not publicly confirm the news, and their reps did not immediately respond to The Times request for comment.

However, that didn’t stop the gossips from weighing in on the the couple’s new arrival. Us Weekly, E! News and People all published reports confirming the birth through unnamed sources.

Meanwhile, TMZ obtained the child’s birth certificate, revealing that Baby Brody-Meester is a girl who was born at 12:12 a.m. on Aug. 4 in Whittier.

Seth and Blair -- er, we mean Adam and Leighton -- named their little one Arlo Day Brody, according to the certificate posted online by TMZ.

Rumors that Meester, 29, and Brody, 35, were expecting first cropped up in March when concertgoers noticed a hint of a baby bump while the actress was performing with her band, Check in the Dark, in Vancouver, Canada, according to OK! Then in May, reports flew asserting that the actress was indeed with child.

The small-screen stars met on the set of their 2011 dramedy, “The Oranges,” and are said to have hung out occasionally during shooting. They were first romantically linked in February 2013, and reports that they tied the knot surfaced in February 2014.

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