And thankfully, a number of women, famous and everyday, stepped up to show the star some support and encouragement for feeling she missed out on a major milestone in her daughter's life.
Williams celebrated her milestone 100th match at the All England Club with a 90th win, needing just an hour and two minutes to see off Russian qualifier Evgeniya Rodina.
Still, Williams said she's not getting too excited as she's still adjusting to tennis after returning from maternity leave.
The absence of the top 10 seeds leaves the tournament open, but for some that is no surprise.
In the last men's quarterfinal, which was suspended because of darkness after the third set Monday night, 2009 US Open champion Juan Martin del Potro defeated Gilles Simon of France, 7-6 (7-1), 7-6 (7-5), 5-7, 7-6 (7-5).
Williams, 36, now heads to the semi-finals to compete against German tennis player, Julia Gorges. "I'll just keep fighting", Williams said. From then on, the result felt inevitable as she served beautifully, levelling the match and then, after a stunning backhand to break for 2-1 in the decider, she eased through the set, serving out to love to take her place in the last four. Also still in the running is No. 12 seed, Jelena Ostapenko of Latvia.
Both two-time Grand Slam champion Kerber and 21-year-old Kasatkina reached the quarterfinals at last month's French Open.
Serena Williams is rightfully, shamelessly confident, which she not only exudes but will also vocalize if asked.
Bertens built a 4-1 lead in the second set with Pliskova appearing to lack energy at times - occasionally making little attempt to chase balls down.
The victor of the Williams and Giorgi match battles Bertens or Goerges in the semifinals. The two met last month in the second round at the French Open, with Williams winning in straight sets. After losing the first set, Williams was able to turn her game around and defeat Giorgi. "Everybody has the same chances to win that match, and I'm looking forward to it".
None of the top eight women's seeds have reached the quarter-finals for the first time since seedings were introduced in 1927 - although Williams' 25th seeding is misleading.