Sharing a video on Instagram Thursday, Williams explored her kids' book The Adventures of Qai Qai, out now, with daughter Olympia. The book, inspired by the social media reaction to Olympia's own baby doll with the name, follows the adventures of the doll and the little girl who loves her.
As Williams shows in the video, Olympia continues to think that the little girl in the book is her. Williams starts by brushing through her daughter's hair, telling her, "Ooh girl, we're going to do your hair today."
Williams suggests they try the same look as the book's main character, to which Olympia says, "that's me."
"That's not, no that's not you," Williams replies, to which Olympia objects again.
"Tell me about your day, we at the salon girl," the mom says, changing the subject. "I want to hear all about your day."
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In a later scene, she reads a line from the book which says "get it babygirl, work that runway," and encourages Olympia to do the same.
"Work that runway!" Serena shouts as Olympia struts around, stumbling briefly before regaining her stride.
She then runs back to her mom, sits next to her and says, "That was cool!"
The athlete, 40, appeared on Good Morning America earlier this month, where she chatted about her children's book.
"Olympia thinks it's her in the book. She thinks the mom is me and she thinks the dad is my husband," she said with a laugh. "It's quite funny because I'm like 'It's not us.' I don't want it to go to her head."
Sharing more about her first children's book, Williams explained that the story includes "some really cool hidden messages about self-confidence" and goes "back to the art about being a kid."
"We can't forget how important it is to use your imagination and play and also believe in yourself," she added.