The general rule is that shoes are required.
I don’t know if they would make exceptions, but I’d highly recommend she wear some foot covering on her feet, even if it’s not traditional shoes.
My youngest daughter has cerebral palsy and we do need to transfer her onto rides that don’t have a wheelchair car.
- when transferring, it’s very easy to hit feet and legs on the sides of the ride vehicle doorways
- the ride vehicle floors are dirty - obviously, people are getting on with shoes they have been walking around the parks with. If it’s raining/has rained, the floor may also be wet or damp
- some ride car floors are not smooth, they have a little bit of rough surface to make them more non-slip
Some of the young ladies in my daughter’s wheelchair dance class didn’t like to wear shoes. In some cases, it was the feel of the shoe (tightness, rough areas, rubbing) and in some cases, their feet had places that protruded out or were not shaped in a way that shoes fit.
Popular types of shoes included water socks or water shoes mentioned by another poster, Muk-Luks, yoga shoes or slippers/slipper socks. Just make sure they are secure and won’t slip off during transfers.