Serena Williams' Newborn Daughter Adorably Flexes Her Muscles in Her Sleep: 'Biceps'

Serena Williams' Daughter Alexis

Serena Williams' baby girl, Alexis Olympia Ohanian Jr., is just like her mama!

The 35-year-old tennis pro and her fiancé, Alexis Ohanian, shared an adorable pic of their newborn daughter on her Instagram account on Friday, where she's seen fast asleep and flexing her tiny muscles.

Simply captioned "Biceps," little Alexis is sporting a navy onesie with the phrase "Smart and Strong like my Mama" written in pink and white.  

RELATED: Serena Williams Shares First Photo of Daughter Alexis and Reveals 'We Had a Lot of Complications'

Alexis Olympia was born on Sept. 1 and is the couple's first child together. Williams first introduced her baby girl to the world on Wednesday, with a sweet pic on her Instagram and another on her daughter's social media page.

"Thinking about mommy and daddy ??‍♀️??‍?," the parents captioned a pic of their baby sleeping and wearing a yellow onesie. 

In a special video shared by the couple earlier this week, Williams revealed that she had a few complications during labor and stayed in the hospital for over a week. 

Hear more of her journey in the video below.