Not a movie, but the show *Little House on the Prairie* from the 70s/80s did 2 episodes featuring characters who stutter, and I think they were done very well. The epsiode "The Music Box" in particular portrayed it with a good degree of accuracy (especially blocks, and showing how different environments/anxiety can impact a stutterer) and compassion. It's a bit hard to watch at times, because it shows how others, especially children, can be cruel, but one of the main characters--as well as others--make up for it in the kindness and acceptance they show the girl who stutters. I was super impressed when I first saw it!