Melbourne Park better be ready, because Serena Williams and her new “training partner” are on their way! The 23-time Grand Slam champion, 39, took to TikTok on January 19 to show her legions of followers one of her final state-side tennis practices before heading off to Australia for the first Grand Slam of the year. In the video, which she reposted to Instagram, Serena was joined by her adorable, three-year-old daughter Olympia!