Williams is mom to daughters Olympia and Adira, whom she shares with husband Alexis Ohanian

Serena Williams is sharing the most life-changing piece of advice she received after having her second baby.

On Thursday, April 4, the retired tennis pro joined Hoda Kotb and Jenna Bush Hager on Today with Hoda & Jenna and opened up about how her life has been since welcoming daughter Adira in December.

“The new baby is amazing. I have to say I am obsessed with her. Oh my gosh, she’s so yummy. She’s like the best, I love her,” Williams, 42, shared.

“We all have sisters. What is it like knowing she has a sister?” Bush Hager, 42, asked.

“That’s one thing Olympia would always say — I want a sister,” Williams said, showing a picture of her holding Adira. “Look at that, I just can’t even take it. So I was so happy when we had the opportunity to have another little girl. I was like, ‘Yes!’ It was like, ‘You want a boy?’ I was like, ‘Uhh…’ I want boys but, I come from, I have four sisters, I’m one of five. So I’m so used to girls.”

Kotb, 59, then asked Williams what it’s like being a mom of two.

“Two is different, but I haven’t experienced it yet because they’re six years apart. So Olympia is in school most of the day and I get to hang out with the baby most of the day. And then when Olympia is home, I get to hang out with her,” she shared.

“Someone gave me the best advice, they said, ‘Spend more time with the oldest cause they’ll remember,’ ” Williams continued. “Isn’t that the best advice? But I do. Because the little one won’t remember. So whenever Olympia’s home, I’m with her. And then Adira, I’m just like, ‘Okay…’ I pretend like I don’t know her as much.”

“You want to make Olympia feel like she’s not replaced,” Bush Hager offered.

“Exactly, exactly. That’s hard,” Williams responded.

Earlier this week, the sports icon was asked in an interview with Byrdie what brought her the most joy out of life, prompting her to say it was her kids. “I can’t say that a Wimbledon trophy holds a candle to volunteering at my kid’s school,” Williams said.