At the start of 2017, sister Venus is beaten in straight sets as a seventh Australian Open is secured and an Open-era record 23rd Grand Slam singles title won. Later we would find out she won while pregnant with her first child. (CNN)Serena Williams insists her desire to win is "still incredibly high" after becoming a mom as she came through a tough test against the hard-hitting Kaia Kanepi to progress to the quarterfinals of the US Open. Williams, chasing a record-equaling 24th grand slam, is playing her seventh tournament -- and a third grand slam -- since giving birth to daughter Olympia last September.