She’s otherwise occupied. Besides, It was established in “The Memaw Materialization” ep. of TBBT that Memaw is short. What I grant that Annie Potts looks and sounds nothing like the actress who played Memaw of TBBT, she at least is more or less the same height (allowing for some age shrinkage). Laurie Metcalf is fairly tall. Not a giant, but something like 5’7.
The “otherwise occupied” is really the deciding factor, though.
In the first season, the show was very vague about Sheldon’s father’s death. There’s a point where he talks about his mother visiting him in Germany when he was 15, but having to leave to help his father put the house back up on the blocks.
George Sr. conceivably could have something in probate for a long time, if, say, he owned a plot of land jointly with a sibling who decided to make an issue of it. Small estates can still get dragged out, and it can be the piddliest thing that does it. Or it could even be something like having two burial plots (it happens), and finally getting around to selling one.
But yeah, exactly when Sheldon’s father died was a movable feast in the first season.
Since then, though, it’s been pretty consistently when he was 14. I think they are going to have to kill George Sr. if the show lasts 5 years.
Also, I don’t mind that the actor was also Jimmy Speckerman. I think he’s good enough to have a very distinct character established for the father, who is different from Jimmy Speckerman. Doesn’t bother me at all.
Missy is awesome, and so is Georgie. I like that the show isn’t always focused on Sheldon. I liked older Sheldon well enough in the seasons of BBT I watched, but a little goes a long way.