I think she could have been an ISFP. I've read quite a lot about her, and find many things in common with her.
It's rare that people look beyond the surface, and are quick to assume, give labels. Most see what they want to see. It's sometimes a cause of hidden saddness in a lot of ISFP's. I think it was true for Marilyn too.
I would guess ISFP, but I don't know that much about her as a person ( she definitely had a public persona....). These quotes do sound very, very NF idealist, and heavy on the Fi. I can see INFP from them, maybe ENFP. Honestly, I just don't see INFPs being so overtly sexy, haha . I know it's partly an act, but she obviously exudes some natural sensuality.
"Charlotte sometimes dreams a wall around herself. But it's always with love - So much love it looks like everything else. Charlotte Sometimes - So far away, glass sealed and pretty." - The Cure