My 11 year old daughter is autistic and still in diapers. We've tried for ages. The school has tried, daycare has tried. She will sometimes go when we put her on the toilet, but only for pp. She will not do #2 in the toilet no matter what. She will only do that in her room looking out her window. It's odd, but that's what she does. We just have to hope someone notices and changes her before she decides it's time to recolor the bedroom again.
She is non communicative so she has no way of telling us she wants or needs to go potty.