Missy's role in season 7 of Young Sheldon showcases how The Big Bang Theory failed to develop her character. In season 6, Missy resorted to extreme measures to gain her family's attention, such as stealing her father's car without a license. However, after a near-death experience, she promised to make amends and goes above and beyond in the season 7 premiere. 

Despite her limited appearances in The Big Bang Theory, Missy left a lasting impact that made her a fan-favorite in Young Sheldon. However, the prequel series still underutilizes her potential. In the season 7 premiere, titled "A Weiner Schnitzel and Underwear in a Tree," Missy takes charge of the household in her mother's absence and proves herself to be efficient and capable. This episode highlights her hidden qualities and demonstrates that she could have achieved more if given the opportunity.

Unfortunately, The Big Bang Theory did not allow Missy to fulfill her potential. 

While her siblings excelled in their respective fields, Missy ended up in a dead-end job and a failed marriage. Despite her leadership skills and emotional intelligence, she did not achieve the success she deserved. It is revealed in Young Sheldon that Missy eventually remarries and has more children, but her career is not mentioned.

 Hopefully, future episodes of the prequel will address this issue. Viewers can catch Young Sheldon season 7 on CBS every Thursday at 8pm ET. The show provides insight into Sheldon Cooper's upbringing in Texas and his pursuit of science and academia, along with exploring the lives of his family and Mee-Maw.