Dawson Casting: Quite possibly the most extreme case of this trope. In 1954's The Secret Storm, the 63-year old Crawford played the role of a 28-year old (a role that was originally intended for her daughter).
Money, Dear Boy: Especially in her later films, which were a far cry from the days when she earned thousands per week as an in-demand actress.
They were all terrible, even the few I thought might be good. I made them because I needed the money or because I was bored or both. I hope they have been exhibited and withdrawn and are never heard from again.
Crawford referred to her experience working on This Woman Is Dangerous regarding this:
I must have been awfully hungry. The kids were in school (and) the house had a mortgage. And so I did this awful picture that had a shoddy story, a cliche script and no direction to speak of...I suppose I could have made it better, but it was one of those times when I was so disgusted with everything that I just shrugged and went along with it.
Urban Legend of Zelda: Rumors have persisted for decades that Crawford starred in a porn film when she was a young woman, and that MGM obtained the master copies of the films and burned them to prevent anything from leaking out. At the time, she was feuding with MGM over her salary, and someone tried to extort money by claiming they had a film of her - which MGM viewed and said was not her. It has also been rumored that she took part in a "peepshow" vignette (where she danced naked) in 1923 to earn enough money to pay for a trip to Chicago - several near-topless photographs of her exist from this time period.
Crawford was intended to star in a reality show/anthology called The Joan Crawford Show, but none of the networks she approached were interesting in pursuing the idea.
She was originally set to be the lead in From Here to Eternity, but was canned by the studio after she demanded on having her costumes be designed by a certain tailor. The role went to Deborah Kerr instead.