Also worth noting that some of it is what Nicole Fosse thinks happened, rather than what anything Gwen told her:
Vulture notes in their recap:
Peter Shelley’s 2015 biography Gwen Verdon: A Life on Stage and Screen, meanwhile, notes that the couple were married “exactly nine months” before James Jr. was born, which doesn’t quite fit the definition of a shotgun marriage, by the usual parameters of human gestation. Let me clear here: I’m not saying anything in this episode (including Henaghan’s implied sexual assault) is a case of questionable dramatic license on the Fosse/Verdon writers’ part. Nicole Fosse is a consultant on this show, and it’s possible Gwen told her daughter more about her first marriage than she ever told any reporter. I’m only saying that even theater geeks who know a lot about Fosse and Verdon are likely to be startled by what this episode depicts."
From Vanity Fair's story:
“Nicole filled in a little of this [backstory] for us,” said Cahn. “Kind of starting with the basic story that, when Gwen was about 16 years old, one of her parents’ friends got her pregnant and then her parents told her to marry him.” This account is depicted in flashback, presenting, for the first time, the circumstances in which Verdon met her first husband. “She met him at her parents’ home,” continued Cahn. “He was a personal friend of the family. He was a theater critic and a little bit of a talent manager and then, shortly after, he was a married man with a serious drinking problem who couldn’t do his job. His very young wife, who had stopped dancing and literally threw away her dancing shoes to be a mother and a wife, was writing his columns for him.”
When Verdon did later speak about that first marriage, she did so obliquely. “I thought being married meant doing the laundry,” she told The New York Times in 1981. “I mean, what do you know when you’re that age?” She added of her husband: “He was a drinker. So he would wind up in Kansas City and not remember how he got there . . . My son was born in March and on New Years Eve, I said ‘That’s it,’ and I went home to Mama. I took my child, my dog and my cats and left.”
Verdon may have kept details of the marriage secret to protect her son, but that doesn’t make them any less infuriating. The idea of Verdon’s parents forcing their teenage daughter to marry the family friend who impregnated her? “That is just a jaw-dropper,” said Cahn, still incredulous over the revelation. “It’s like, ‘What?!’ Why hasn’t there been a feature film about [Verdon] every 10 years? That story is crazy. He was her parents’ friend!”
When asked how Nicole came to this realization about her mother’s first marriage, Cahn said, “It’s tricky talking to someone about their life and their parents’ life, and how she kind of put pieces together as she grew older. I have actually had a similar experience—my parents both passed away, and in the last few years, I have kind of been putting stories together that I heard as a child. Looking at them from the perspective of an adult, thinking, Oh, that’s what that meant. That’s what that was a euphemism for . . .”
“I think there were a lot of pieces that she started to piece together as she looked back at this as an adult, and as a parent,” explained Cahn. “Little scraps that she heard from her parents or their friends over the years and kind of put together into a more complete picture of what happened in her mother’s young life.”
As with all of these series--Feud, American Crime Story, etc.--portions have to be taken with huge heaps of salt. Yes, this is Nicole Fosse's version of her parents (and the people around them), which may or may not be completely accurate.