[luvbach1]

As to why...could be as simple as, much like Marilyn Monroe, she was getting older...

Not wanting to contradict you, but Marilyn was only 36, not at all old to me.

[M1903A1]

True...at the same time, “Hollywood years” (especially back then) can be brutally different, especially if you’d not had much movement from a given “range” of roles, and there’s plenty of younger and fresher versions coming right behind you.