I understand what OP is trying to do. The kids don't want the direct interaction, however they will be present (it's not like they aren't on the trip with mom&dad). They will have the "memory" of seeing the characters, seeing mom or dad meet the character and get the autograph for them. Meanwhile, the child stands back (next to the picture-taking parent) to watch and avoid direct interaction. My DD does not have an ASD diagnosis but has many similiarities. It's how their brains are wired, she just loves photo albums and discussing who/what/where/when about each picture, whether or not she was directly involved. Good luck to OP. Yes, adults may stand in line and get autographs and pictures taken with characters. If you point out your children, the characters will wave to them and not force them to participate. Enjoy your vacation!