Is her unwillingness to step aside related to a mistrust in Charles' abilities? Or is she just trying to keep up a mostly held traditional of succession after death?
I take your point about her possible mistrust of Charles, although latterly I believe it may have dissipated. I think her "unwillingness to step aside" has rather more to do with a devout and genuine faith. I doubt she's ever put a foot wrong regarding her position, but it would be puerile to assume that everything in her domestic garden was always rosy -one needs only look at the lives of her children- but it's never possible, regardless of wealth and position, to have everything.