~Taxi Driver pics above~ I can see it. There was a television series called
Paper Moon, same as the movie. That was my first memory of Jodie Foster. I was still a kid like her but I could tell she was a pretty darn good actress at the time. Then she did
Taxi Driver as a teenager on top of that.
She could pull off the tomboy-ish side of Leia, especially her sense of independence. What worked against her in my opinion was that her appearance matched her actual age. The twins were supposed to be 18 or 19 for
Episode IV and Carrie Fisher was 19 when she was cast. Foster was 13 or 14.
Having Foster play up in age might have been challenging for George Lucas at the time. It did not stop Lucas from having Harrison Ford, who was in his mid-thirties, play down in age. Admittedly, Foster and Ford would have been initially awkward to look at on screen side-by-side for the first movie. It would have been less so for me by
Episode V.
Most fraternal twins look different but Fisher and Mark Hamill's facial differences were distinct. Hamill and Foster would have been much more similar, even their hair.
Foster was in
Freaky Friday, so she proved she could do lighthearted big screen stuff. The auditions would have been interesting to watch her interact with Ford and Hamill, multi-actor tryouts Lucas made certain there would be real chemistry between the eventual main cast. I would love to see if she did any auditions. Supposedly, Lucas did offer her the role, but filming conflicted with her Disney commitments.
I am 100% happy Fisher was Leia. Loved what she did with the role in everything she did. I even enjoy producers incorporating her old lines into video games, lol. That said, in hindsight, Foster would have finished the last batch of films. Fisher's life caught up with her. She died too young.