Serena Williams Says Her Life Is 'Totally Different' as a Mom and Investor: 'My Second Career'

Kezi Ban Serena Williams

Serena Williams' days look vastly different now than they did just a few years ago.

Tennis is still, of course, a major focus, but the 23-time Grand Slam champion has diversified her interests as she's diversified her portfolio, and taken on new roles like leading a venture capital firm and becoming a mom to the nearly-5-year-old Olympia.

"Now when I prepare for a tournament, I practice in the morning, I take VC calls in the afternoon and then I spend time with Olympia, and that didn't happen five years ago," Williams, 40, tells PEOPLE.

On a recent day, the tennis ace says, she trained, worked in her office on her VC firm Serena Ventures and then spent the rest of the day playing games with Olympia. "It's totally different," she says. "I can't imagine having this conversation with you a little while ago and saying that this is what my life looks like."

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Williams' venture into investing has been the perfect "second career" for the four-time Olympic gold medalist, who says her parents instilled in her the importance of financial independence and money management. That's something she's now teaching Olympia, her daughter with husband Alexis Ohanian.

Kezi Ban Serena Williams

"I am a huge proponent of financial independence and education, and accessibility," Williams says. "So those things are really important for me to teach my daughter and also important for me to raise awareness."

That's part of why she partnered with Cash App for their new "That's Money" campaign. Williams stars in a new ad, which shows her using Cash App after a night out to pay the babysitter before grabbing leftover pizza and bringing a stuffed animal into Olympia's room.

"I am a huge proponent of financial independence, education and accessibility," Williams says in a release. "I want to use my platform to raise awareness around the opportunities money management tools like Cash App have to offer, so working together was a no-brainer.

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Another way Williams is using her platform is by working to make Serena Ventures as diverse as a possible, especially in the venture capital world where very few companies are.

"We invest in women, we invest in women of color, we invest in people of color," she tells PEOPLE. "A lot of these companies talk about diversity, but they just talk about it. It's because it's a good subject that they bring up, but they don't really do a lot of things about it. And so at Serena Ventures we do, we talk about it. We be about it."