Serena Williams during their women's singles match, on the third day of the Wimbledon Tennis Championships in London, Wednesday July 4, 2018. (AP Photo/Kirsty Wigglesworth)

Serena Williams  was busy practicing at the All England Club on Saturday when her little girl Alexis Olympia, 10 months, walked for the first time.

Serena tweeted: "She took her first steps ... I was training and missed it. I cried."

Serena had previously admitted she prayed and "cried a little bit" when she stopped breastfeeding Alexis.

She said: "I literally sat Olympia in my arms, I talked to her, we prayed about it. I told her, 'Look, I'm going to stop. Mommy has to do this.' I cried a little bit not as much as I thought I would ... After [I stopped breastfeeding], like literally I lost 10 pounds in a week. It was crazy. I just kept dropping. I was like, that's when I learned that everything was different. Sorry to go on about that. I wanted to say that so women out there know that's not true. Everyone takes things different. I think it's important for us to share that message."

She also shed a tear every time her daughter did in the early stages of motherhood.

She explained: "It's tough in the beginning. The baby's crying all the time and you don't know why - you don't know if it's gas, you don't know if she's sick, you don't know if it's just colic. So I just started crying with her because I couldn't help her and I wanted to help her and I couldn't, so I just started crying."