Young Sheldon inadvertently revealed what happened to Missy after she last appeared in The Big Bang Theory for Sheldon's wedding in season 11.

Young Sheldon reveals what happened to Sheldon's sister, Missy, after The Big Bang Theory. Sheldon's sister was the first member of his family to appear in the original sitcom, coming to the show as early as season 1, episode 15, "The Porkchop Indertiminacy." Since then, she appeared sporadically throughout The Big Bang Theory's 12 seasons on the air, and her story continues through the spin-off prequel, Young Sheldon. Young Sheldon covers Sheldon's first year of college in season 4, which means that he spends much of his days away from his family, particularly his siblings.

However, in Young Sheldon season 4, episode 11, "A Pager, A Club, And A Cranky Bag Of Crinkles," Sheldon and Missy shared a couple of scenes together. While in their room, Sheldon asked Missy how her social life was going. While she's not book-smart, she's empathic and agreeable, which makes it easy for her to find friends. In the narration, he inadvertently revealed what happened to Sheldon's sister by saying that Missy has loving family and friends due to this particular trait, before adding that he does have those too, plus a Nobel Prize in Physics, so his life turned out to be better in the grand scheme of things.

Missy Is Happy After The Big Bang Theory

The reveal of what happened to Sheldon's sister may not have major implications for what the foreseeable future would be like for Missy in Young Sheldon, but it does shine some light on her life after The Big Bang Theory concluded. The voice-over narration suggests that Missy was married after the events of the original series. The last time she appeared on TBBT, just before Sheldon's wedding to Amy in season 11, she was separated from her husband, suggesting an entirely different fate for Missy.

While she was thrilled about this, she was less enthused about being pregnant. At that point, she already had a son. Previously, Young Sheldon revealed what happened to Sheldon's sister, and that she ultimately had four children, meaning that she got pregnant twice more. Neither series has yet to confirm whether or not Missy patched things up with her estranged husband, at least during the time of The Big Bang Theory season 11, episode 24, "The Bow Tie Asymmetry," but it's nice to know that she eventually found happiness in her personal life.

Why Young Sheldon Needed To Set Up Missy's Life After Big Bang Theory

Missy is often the butt of the joke on Young Sheldon, which makes her appearance on The Big Bang Theory quite affecting. When Missy was revealed on TBBT, she was going through a rough time. She was pregnant — and none too thrilled about it — and separated from her husband, making many wonder what happened to Sheldon's sister. Missy ended up being cheated by both shows, becoming a running joke in Young Sheldon and being treated as an object/plot device on TBBT. The prequel series' reveal of Missy's happy ending after the flagship show's timeline pays off her character, provides closure, and puts an optimistic slant on Missy.

After all, Missy really didn't do anything wrong – at least certainly nothing warranting the abuse she endures on both shows. If Missy did stay separated from her husband, the identity of her partner makes for an intriguing question when it comes to what happened to Sheldon's sister. All of Sheldon's male friends in The Big Bang Theory attempted to go out with her when she initially visited Pasadena, but she was particularly smitten by TBBT's Raj. Considering that the astrophysicist was the only one left single at the end of the show, it would make for such a great twist if Young Sheldon revealed that they ended up together.

There's A Young Sheldon Missy Problem

Young Sheldon, while a great entry into the TBBT universe, has unfortunately been known to create a fair few plot holes, with what happened to Sheldon's sister seemingly being one of them. Characters like George Sr. have been painted in a different light on The Big Bang Theory. However, it seems that Missy's character has received the most flagrant mistreatment. Missy received a fair few bizarre tonal moments in Young Sheldon season 6, as her story was suddenly treated with the utmost seriousness, even more than Sheldon's, and she uncharacteristically ran away from home in episode 16, "A Stolen Truck and Going on the Lam."

In addition, Georgie mentions in TBBT that Missy didn't start rebelling until after George passed away, when Young Sheldon season 6 made it clear that it started much earlier, due to Mary and George constantly forgetting about her. In a way, Young Sheldon has made Missy's TBBT story more tragic, and it's obvious that the series doesn't know how to handle her character. Missy oscillates between being given more attention than the protagonist and being sidelined completely, and her latest arc caused a tonal shift that felt out of place on Young Sheldon. While what happened to Sheldon's sister after The Big Bang Theory is good news, the prequel series needs to figure out how to handle her storylines.