Serena Williams has made a career of achieving the improbable.

She learned the game from her dad, himself a self-taught coach, on the glass-strewn public courts of Compton, Calif., growing into perhaps the greatest tennis player in the game’s history. She has won more Grand Slam titles than any woman in the Open era and trails only Margaret Court (24 to 23) in the all-time annals. And she has won six US Open women’s singles titles, tied with Chris Evert for the most in the Open era.

In 2018, she’ll have a chance to do something that only two women have done before her: win a US Open title as a mom.

Serena announced Wednesday that she is pregnant and will sit out the rest of the 2017 season. Predicting the future is a fool’s errand, but for anyone who doubts her resolve to return to the top of the game as a 36-year-old in 2018, remember this: She won the Australian Open earlier this year when she was two months’ pregnant (pictured above).

The only other woman to even approximate that feat is Court, who was pregnant when she reached the 1971 Wimbledon final, where she fell to Evonne Goolagong.

Both women play prominently in Serena’s potential future as a tennis super mom Grand Slam winner. Court, in 1973, and Kim Clijsters (pictured below), in 2009 and 2010, are the only two moms to have won a US Open women’s singles title since the dawn of the Open era in 1968. The only other mother to have won a Grand Slam title in the Open era is Goolagong, who did so at Wimbledon in 1980.

Of course, Serena may not be the next to join that elite club. Two-time Australian Open champion and US Open runner-up Victoria Azarenka is slated to return to the tour this summer, a little over seven months after the birth of her son.