We just returned with my 78 yo grandmother, who is mobile but in a wheelchair for park touring. I highly recommend One Man's Dream at DHS, and the movie that follows. She can take her time, enjoy seeing vintage toys and tv/ movie clips she would likely remember, and the movie afterward is inspirational and interesting. So many people skip it in lieu of headliner attractions and it's a shame. It's never been crowded in there in my experience.
If she can't sit for a long time to wait for the fireworks, the Wishes Dessert Party could be a nice option for you.