This is a bit of a stretch, but Dorothy, from Return to Oz. It's not really explicitly SA, but the idea of being lonely, isolated, and considered defective and strange, even by people who love and care for you, is a major theme in that movie. When Dorothy escapes the shock therapy she was sent to for her 'insane' talk about 'a place that doesn't exist' (Oz), and actually winds up back in Oz, her group of friends there consist of a robot, a flying sofa, a childlike pumpkin-headed stick man, and a chicken. The main villain Nome King starts out looking very rock-like, and grows progressively more humanoid. The more human he becomes, the crueler he gets. The whole movie is probably one of the most beautiful, dimensional, nuanced, and, (in my experience) meaningful depiction of mental illness in a fictional film that I have ever seen, and all in a children's film made by Disney in the 1980's! It is probably the movie that I have most identified with, and has most effected me, and I highly recommend it.