Raegon Revord played Sheldon's sister Missy for seven seasons on "Young Sheldon," and through all that time she never changed her hair. Well, that's not entirely true — sometimes she got to wear ...

Some of the best "Young Sheldon" episodes are more painful than funny, and Raegan Revord, who plays Missy Cooper in "The Big Bang Theory" spin-off, understands this sentiment better than anyone ...