Maggie is a famous British character actress who has made almost 50 films and who knows how many BBC appearances. I first met her in the Agatha Christie mystery "Evil Under the Sun". You might recall her as the Mother Superior from "Sister Act" and the sequel, or as the elderly Wendy from "Hook". More recently, she's been in "Tea with Mussolini" and "First Wives Club". She is simply splendid. Oooodles of character.
Diana Rigg, however, would do well. I just don't like her. I know, I'm the only person in the whole world who doesn't like Diana Rigg!!!
If we stray at all from British actors, can we consider Angelica Huston?