- "They stole my life's work, so I don't have much to lose."
- ―Jane Foster, in Thor.
Marvel Studios stated in an announcement that the character will be updated from the comics' initial portrayal for the feature adaptation. When asked why she took the role, Natalie Portman replied, "I just thought it sounded like a weird idea because Kenneth Branagh's directing it, so I was just like, 'Kenneth Branagh doing Thor is super-weird, I've gotta do it.'"
Portman also stated that she really wanted to do a big effects movie that emphasized character, and getting to do it with Branagh was a new way of approaching it, relative to Star Wars. Regarding her preparation for the role Portman remarked, "I signed on to do it before there was a script. And Ken, who's amazing, who is so incredible, was like, 'You can really help create this character'. I got to read all of these biographies of female scientists like Rosalind Franklin who actually discovered the DNA double helix but didn't get the credit for it.
The struggles they had and the way that they thought – I was like, ‘What a great opportunity, in a very big movie that is going to be seen by a lot of people, to have a woman as a scientist'". Portman stated, "She's a very serious scientist. Because in the comic she's a nurse and now they made her an astrophysicist. Really, I know it sounds silly, but it is those little things that makes girls think it's possible. It doesn't give them a [role] model of 'Oh, I just have to dress cute in movies'".