Thereafter, it was a one-way run for the 13th seeded German player who won the decider by six games to one.
Only three mothers have won Grand Slam titles in the Open era - Belgium's Kim Clijsters and Australians Evonne Goolagong Cawley and Margaret Court - but Williams is showing strong evidence that she can become the fourth. "To be here. To be in the semifinals". "I knew we were both moms, and I'm not sure how often that's happened, if ever".
Williams, asked whether she's felt any pressure during this tournament, said, "This is only my fourth tournament back". I don't feel I have to win this; I don't feel I have to lose this. I'm just here just to be here and to prove that I'm back.
Goerges admitted it had been tough playing her close friend and occasional doubles partner on tour.
"But I'm going to prepare well for it, going to be probably long rallies".
Williams never was anxious about losing. "I'm fighting to the end and it helps me, gives me more confidence", said the youngest player left in the draw.
Asked if it had been a flawless display, former world number one Williams said: "I'm a perfectionist".
A second break allowed her to serve for the win at 5-1 and she had a match point, only for Ostapenko to find her range and stay alive.
She now has a 39-35 record when losing the first set at a major. The reprieve was only momentary for Hsieh, as Cibulkova regained her composure to break and take the first set, 6-4.
"I just want to be more of that role model for my daughter, for lots of people out there that just want to be inspired".
Kerber took advantage of Kasatkina's erratic serving and errors to return to the last four.
But Pliskova, who reached number one in the rankings after Wimbledon a year ago, found some fight and capitalised on a loose game by Bertens that allowed her to break back and level the set at 4-4.
Still, Kerber had some trouble closing things out.
She has bounced back in 2018, winning more than 75 percent of her matches and a title while racking up 10 wins vs. top-20 players.
In March, she lost in the first round of the Miami Open to Naomi Osaka, leading to a hasty exit in which she bypassed a postmatch media session.
Kerber and Kasatkina are the only two women to reach the second week at all three majors this year.
In a match that featured eight breaks of serve - four in the first five games - Ostapenko was able to elevate her game in the crucial moments. In fact, photographers have captured Drake, 31, courtside at Williams' matches since 2011. "Everybody has the same chances to win that match, and I'm looking forward to it".
Ahead of the big game in London, Williams admitted to "Good Morning America" that her body had changed after the baby. The last time two German women reached any Grand Slam semifinals was at the 1993 French Open, featuring Steffi Graf and Anke Huber.