NEW YORK - American tennis star Serena Williams shared pictures and videos of her newborn daughter, Alexis Olympia Ohanian Jr, on Instagram on Wednesday (Sept 13), almost two weeks after her Sept 1 birth.

Her Instagram post elicited congratulations and well-wishes from celebrities including supermodels Gigi Hadid and Lily Aldridge.

Williams had teased her fans about the announcement on Tuesday (Sept 12) in an Instagram post alongside her fiance, Reddit co-founder Alexis Ohanian with the caption, "... but are you ready?"

The former world No. 1 shared a montage of videos on Instagram stories, detailing her pregnancy timeline from her first ultrasound scan to her journey during the three trimesters before cheekily revealing that her daughter was already the proud winner of one Grand Slam - a nod to Williams' victory in the Australian Open in January while she was already an expectant mother.

According to her coach, 23-time Grand Slam singles winner Williams - who has been on hiatus from the sport since - is aiming to make her return at next year's Australian Open.