who plays young sheldon's grandmother
They're both much sleazier roles than Sheldon's dad. Raegen Revord (Missy Cooper) plays Sheldon's twin sister. Young Sheldon is going to be her breakout, but she's previously appeared on Modern Family. Annie Potts (Meemaw) plays Sheldon's grandmother, but she will always be best known for playing Mary Jo Jackson Shively on Designing Women. She was nominated for an Emmy for Love & War in 1994 and SAGs in 1998 and 1999 for Any Day Now.