The writer of Doctor Strange confirmed Scott Derrickson wanted Jessica Chastain to portray Christine Palmer in the 2016 movie and even approached her to join the Marvel Cinematic Universe.
Speaking to Junkfood Cinema, writer C. Robert Cargill, revealed how close Chastain came to playing Christine Palmer. "This is the interesting thing that Hollywood’s starting to find out, is that a lot of the actresses out there want to be superheroes as much as the actors do," said Cargill. I know this happened with Scott [Derrickson]. He went to Jessica Chastain to get her on Doctor Strange, because we were considering her."
He went on to explain why Chastain turned down the chance to play Palmer: "She’s like, ‘Hey, look, this project sounds awesome, and I would love to do it. But I’m only going to get one shot at being in a Marvel film and becoming a Marvel character; and I trained in ballet, and I really want to wear a cape.’ And that was the coolest rejection ever. She wanted to be in a Marvel movie, but she wanted to be the superhero, not the badass doctor Night Nurse."
Rachel McAdams went on to play the role in the 2016 film and although she featured prominently in Doctor Strange, the movie didn't include her transition into the heroic Night Nurse. Kevin Feige said this could be explored in further movies, but as it stands, it looks like McAdams won't be back for the upcoming Doctor Strange in the Multiverse of Madness.
Doctor Strange in the Multiverse of Madness stars Benedict Cumberbatch and Elizabeth Olsen. The film is currently scheduled to hit theaters May 7, 2021.