Mandy never physically appeared on The Big Bang Theory, but Young Sheldon reveals her secret impact on the sitcom.
Introduced on Young Sheldon season 5 as Georgie's newest love interest, Mandy eventually becomes a mainstay in the CBS family sitcom after she discovers that she's pregnant with Mary and George's first grandchild.
Unlike the rest of the Cooper family, however, there's barely anything known about her future, because she was never on The Big Bang Theory.
While the jury is still out with regard to what happens between her and Georgie, as well as, their upcoming baby, Young Sheldon has established how Mandy affects the storytelling of the nerd-centric sitcom.
In Young Sheldon season 6, episode 7, "A Tougher Nut and a Note on File" Mandy's parents are finally introduced as Jim and Audrey McCallister.
Georgie is able to quickly establish a relationship with his girlfriend's father, who owns a local tire shop - and in The Big Bang Theory, Georgie is the successful business owner of Mr.
Tire. While the eldest Cooper kid has always had a penchant for entrepreneurship, he has never dabbled in the industry that he ends up in until he forms a connection with Jim. So, regardless of Georgie and Mandy's future, their connection is already confirmed to have an impact on his life on The Big Bang Theory.
Despite Georgie's limited The Big Bang Theory appearance, the sitcom efficiently established the character.
Aside from being a successful businessman, Georgie took over the family after George unexpectedly died because Mary was too grief-stricken to function, Missy was out being a teenager, and Sheldon was overseas for his study grant.
Young Sheldon showing Georgie taking care of his siblings in Young Sheldon season 6, episode 8 and Mary following her big argument with George in the season 4 finale foreshadow his future role as the main man of the Cooper household.