Raegan Revord, who portrays Sheldon's twin sister Missy in Young Sheldon, is grateful that Missy didn't make more appearances in The Big Bang Theory. Although an adult version of Missy appeared twice in the parent show, Revord believes that her absence allowed her to create her own interpretation of the character. This creative freedom is beneficial for actors in prequels where the fate of their characters is already known. While Missy's absence may have been a missed opportunity for TBBT, Young Sheldon has showcased the hilarious relationship between the twins and given Revord the chance to make Missy her own.