The season 4 finale of Young Sheldon sets up Missy's arc in The Big Bang Theory. Throughout the season, Missy grows up and begins exploring romantic relationships, while her twin brother Sheldon also experiences puppy love. In the finale, Missy suffers her first heartbreak when she discovers that her boyfriend Marcus spent time with another girl. This leads to a series of events in the Cooper household, including an argument between their parents. Upset, Missy decides to run away, but Sheldon is able to pacify her and they camp out together in an unused cabin.
This episode highlights how romantic relationships deeply affect Missy, causing her actions to be dictated by her feelings. In The Big Bang Theory, Missy devotes herself to a marriage that doesn't work, and as a result, her life lacks the same level of development as her brothers' careers. Despite being overshadowed by Sheldon, Missy is shown to be intelligent, wise, and street-smart. Her outburst at her mother in the Young Sheldon finale about everyone always taking Sheldon's side is justified.
While The Big Bang Theory has ended, Young Sheldon has the opportunity to reveal more about Missy's future. In the recently-finished season, there was a passing comment about Missy being happy in her life without further detail. Hopefully, moving forward, Missy's story continues to evolve, allowing her to become a fully-formed character in her own right.
