Serena Williams' baby daughter Alexis Olympia's first word was "momma".
The 38-year-old tennis ace's two-year-old daughter - whom she has with husband Alexis Ohanian - has just started speaking and she shared that as well as "momma", the little tot also knows how to say Laura, the name of their pet pooch, and she even knows how to put her shoes on.
Asked about Alexis' recent milestones, Serena told E! News: "Everything at this phase is new.
"She is learning to put her own shoes on which is such a big milestone for me because before I had to do it and now I can tell her to do it herself.
"She is starting to talk, and they don't really speak until they are two.
"So she is starting to talk and is learning new words and phrases.
"She's understanding phonetics and is repeating what we are saying - her first word was 'momma!.'"
Asked how she managed to get her to say it, she replied: "I drove her every single day to say it, so 'hello!'.
"She also always hears me calling our dog Laura because she is an older dog. So that was her second word."
Alexis also knows how to say "dadda" but sometimes she gets "momma" and "dadda" confused.
Asked how her spouse reacted when their daughter said "momma" first, Serena admitted:"It was hard for Alexis, but he takes it in such great stride.
"She calls him momma from time to time, but she does also now call him 'dadda' and he loves it."
The sports star - who tied the knot with the 36-year-old Reddit co-founder in November 2017 - also revealed the secret to a successful marriage is being "loving", having "great communication", and praying daily.
She shared: "It takes a lot of time and effort. He travels a lot. It's about having great communication and understanding.
"And above all, it's all about [being] loving.
"That's the most important quality anytime, and it covers everything.
"We FaceTime a lot. We have prayer time at night.
"That's really special. We always do that, we try not to miss it a lot."