Susan may have been too young to play Margo,but not too old to play Eve. Anne Baxter was several years younger then Susan but not by much and she (Anne)
didn't look like a kid. I think Susan would have made a terrific Eve.

Elaine...I totally agree with you. WHY did they not even consider Susan..as Eve? Yes, she would have been the right age and had the 'right, cunning' acting ability to do a great job as the younger star, trying to replace the older star.

According to the book, 'the only two' who were 'iron-cast' from the beginning..were Celeste Holm and Hugh Marlowe. That casting, apparently, never changed from the beginning, although 'other star names' were put on 'the list' of 'maybes'.

I do think that the EVE role would have been a 'big one' for Susan..and 'why' she would be overlooked and pushed for the MARGO role is a mystery. I think it was because Susan had just made 'big noise' in "HOUSE OF STRANGERS" and he was only looking for 'her' to be in the biggest role in the film. Then..in the end, he decided she was too young for Margo (of course she was) and therefore, was taken 'off any other roles' in the film.

A bad move..in my opinion (an apparently, yours too).