uma-thuman-birth-230.jpgUma Thurman and boyfriend beau Arpad Busson welcomed a baby girl on Sunday, according to a source for Us Weekly.

Uma has two children, Maya, 13, and Levon, 10, with ex-husband Ethan Hawke, and this is her first child with Busson, who she's been with off and on since 2007. The two got engaged in 2008, and despite calling off their engagement in 2009, they reunited last year.

"Uma was definitely not planning on having another kid. It was a surprise," a source told the mag earlier this year. "But she's over the moon about it, very excited."

No word on what Uma is planning on naming her bundle of joy, but we'll keep you posted!