Serena Williams Reaches '10 Million Followers On Instagram'... Posts Daughter's Photo To Celebrate

She's consistently setting milestones personally and professionally. And Serena Williams was a champ in the former category as she surpassed 10 million followers on her Instagram feed yesterday.

And the 37-year-old tennis superstar commemorated the event by posting an adorable photo of her daughter Alexia Olympia, one, with the caption: 'For my 10 million followers, thank you!'