https://screenrant.com/how-old-missy-is-young-sheldon-big-bang-theory/

Missy is one of Young Sheldon's protagonists despite only appearing occasionally on TBBT, but how old is Missy Cooper in Young Sheldon and TBBT?

The show has been on for six years and she was nine when it started so she is about 14 in this season of the show.

I dont know what season she was on the series but it has been about twenty years later so she is in her early to mid 30's. It has not been shown how many years it has been since the end of Young Shedon (which hasnt ended yet) and Big Bang Theory. So I guess she was about 35 on Big Bang and Georgie near 40.

^^^ I could be wrong, but right now Missy and Sheldon are still about 11 or 12 because of how slow the timeline has moved along. Missy was singing "Achy Breaky Heart" during one scene earlier this year and that song got released in 1992. If George had not dropped out of school, he would be in his second year of college now. Last season is when he dropped out when it should've been his first college year.

God bless you always!!!

Holly