Serena Williams is now a mother of two. The 23-time Grand Slam-winning legend has given birth to her second child, Adira River Ohanian.

Williams's husband, Alexis Ohanian, posted on social media about the occasion on Tuesday: "A happy & healthy newborn girl and happy & healthy mama. ... You're the GMOAT."

Williams herself debuted a video of Adira with the full family on her TikTok account later on Tuesday:

Williams announced her pregnancy in May ahead of her attendance at the Met Gala with husband Ohanian.

Adira's birth makes Williams's eldest daughter Olympia a big sister. Olympia will turn six years old during the upcoming US Open.

Read more: 'Serena Williams: In the Arena' documentary series coming to ESPN

Williams, 41, will mark her first full year of retirement soon, having last played at last year's US Open. Along with her 23 Grand Slam singles titles, Williams spent 319 weeks ranked World No.1 and won 14 Grand Slam doubles titles alongside her sister Venus.