The first flashback arrives in the second episode, introducing us to a young Cindy. The 16-year-old is in the midst of having sex with a classmate in her high school locker room, and it's revealed that not only does he have a girlfriend (who isn't Cindy), but that she's pregnant with his child. He doesn't realise she's pregnant, though, and she refuses to tell her parents who the father is.
In a later scene with her younger sister, Joy, Cindy tells her why she can't give up the name of who got her pregnant: she actually loves him and doesn't want to ruin things. After having a heated conversation with her father about lying — which connects to current-day Cindy's plight with Taystee — her parents ship her off to Michigan to have the baby in secret. By the end of the episode, it's implied that Cindy's mother is raising the baby as her own daughter, while Cindy ignores the child altogether.