Serena Williams and her fiance, Reddit co-founder Alexis Ohanian, have welcomed their first child, reports say.

Palm Beach Post reported a source close to Williams confirmed the two welcomed a baby girl Friday.

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Reports emerged earlier Friday that the tennis superstar was in labor at St. Mary's Medical Center in West Palm Beach, Florida. WPEC reported that she checked into the hospital Wednesday and labor was induced Thursday night.

Beyonce was one of the first to congratulate Williams, posting a message to her on Instagram.

Williams had a baby shower Aug. 4. More than 70 of her friends -- including sister Venus Williams, singers Kelly Rowland and Ciara and actresses Eva Longoria and LaLa Anthony -- were in attendance.