Isn’t Gillian too tiny to play Margaret Thatcher? Thatcher wasn’t tall, but she wasn’t short either and she was taller and more imposing than Queen Elizabeth. Colman’s height is 5′ 7″.

There’s not one actor in The Crown who resembles to their character, so I guess it doesn’t really matter if she doesn’t look exactly like Thatcher. Plus, people’s size doesn’t matter on tv. There’s many ways to correct or hide that.