The 23-time singles' major champion gave birth to her first child in September, having won last year's Australian Open while in the early stages of pregnancy.

Williams is not at Melbourne Park to defend her title, as she regains full fitness after a difficult birth in which she revealed she suffered blood clots after daughter Alexis Olympia was born on 1 September via emergency C-section.

Serena has done, and won, it all in the world of tennis, but it seems some aspects of motherhood are proving tougher to master.

She posted on Twitter: "I've conquered a lot of things... blood clots in my lungs- twice... knee and foot surgeries... winning grand slams being down match point... to name just a FEW but I found out by far the hardest is figuring out a stroller!"

Williams is expected to return to the court in a one-day tie-breaker event at New York's Madison Square Garden in March, ahead of entering the BNP Paribas Open in Indian Wells.