Serena Williams has joked that her four-year-old daughter may be a "baby Mozart" as she is teaching the tennis star to play the piano.MORE: Serena Williams leaves fans speechless in gorgeous fitted dressOlympia is a fan of tennis, the sport her mom plays, but Serena admitted that the toddler is more into the arts.WATCH: Serena Williams jokes her four-year-old daughter may be a 'baby Mozart'"She likes tennis, but I don't know.