The recent season of Young Sheldon provided some insight into what happened to Sheldon's sister, Missy, after The Big Bang Theory. In an episode titled "A Pager, A Club, And A Cranky Bag Of Crinkles," Sheldon and Missy have a conversation about her social life. It is revealed through Sheldon's narration that Missy has a loving family and friends due to her empathetic and agreeable nature. He also mentions that while his life turned out better in terms of winning a Nobel Prize in Physics, Missy found happiness as well.
The reveal of Missy's life after The Big Bang Theory indicates that she got married and had children. During her last appearance on the show, she was separated from her husband, but it seems that she eventually patched things up with him. Young Sheldon previously revealed that Missy has four children, so it can be inferred that she got pregnant twice more after her initial son.
This revelation serves as closure for Missy's character, who often became the subject of jokes in Young Sheldon and was treated as a plot device on The Big Bang Theory. It puts a positive spin on her story and provides an optimistic outlook for her personal life. There is speculation about the identity of Missy's partner, with some fans hoping for a twist where she ends up with Raj, as she showed interest in him during her visit to Pasadena in The Big Bang Theory.
However, Young Sheldon has faced criticism for inconsistencies and plot holes, including how Missy's character is portrayed. Her storyline in the sixth season of Young Sheldon took a serious turn, deviating from the comedic tone of the show. It also contradicted previous statements made by Georgie in The Big Bang Theory regarding Missy's rebellious phase starting after their father's passing, whereas the prequel series suggests it started earlier due to parental neglect.
In conclusion, Young Sheldon confirms that Missy found happiness in her personal life after The Big Bang Theory. The revelation provides closure for her character and a positive outcome. However, the prequel series needs to address inconsistencies and handle Missy's storylines more effectively to maintain continuity within the TBBT universe.