Hi. My experience is limited to Disneyland, but I assume that it carries over for all relevant purposes.

First of all, for something like $40/day they should rent your daughter an electric cart, which is great. Call ahead though to make sure that they don't have any age restrictions which can't be waived in the event of significant disabilities. Even if you have to push her in a wheelchair there is one little secret of the Magic Kingdom I'm about to make public: people in wheelchairs/scooters go (along with their families) to to head of almost every line!

As to rides, I found that they didn't exacerbate my RSD one bit. The roller coasters did however give me enough chest pain to put me in the hospital for a couple of days, but that was only because at age 54 I now have a history of cardiac artery disease, nothing to do with RSD/CRPS-1.

Finally, I would do whatever you think is most appropriate for dressing your daughter in order to be out in warm, sunny and humid weather.

Good luck and enjoy!

Mike