July 8, 2012 at 2:58 PM ET
Updated Monday, 1:50 p.m. PT: Penelope Scotland Disick isn't the only baby girl with famous parents who made her debut this past weekend! As Us Weekly reported on Sunday, Sienna Miller and her fiance Tom Sturridge welcomed their first child over the weekend in London -- and a source now confirms to Us that the bundle of joy is a girl!
The British actors have been dating for over a year and debuted signs of their engagement -- Miller's dazzling diamond engagement ring -- in mid-February.
After remaining mum about her pregnancy for several months, the G.I. Joe: The Rise of the Cobra actress, 30, finally opened up to British Vogue in April.
"Even though I'm under strict instructions not to say anything as it would completely defeat the point of everything I've tried to achieve in the last eight years," the resolutely private Miller (who famously dated Jude Law) expressed to the mag. "I'm feeling fine ... It's all progressing nicely and it's very exciting."
Despite the couple's silence about their new addition to their family, Miller and Sturridge, 26, made no hesitation in stepping out in public on several celebratory occasions.
In May, the couple stole some time away in Portofino, Italy for a babymoon. A week later, they got decked out to celebrate Sturridge's BFF Robert Pattinson's 26th birthday at Gordon Ramsey's restaurant in London, England.
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