Hi Jackie,
Awesome news that you beat cancer! You give hope and inspiration to everyone around you. So glad to hear that you are planning a trip to Disney World in November. Its an exciting time to visit!
I probably wouldn't send a 9 year old on an attraction alone unless it was something like the Mad Tea Party where I could keep my eyes on her. I think you may be surprised at how many rides you should be able to do. There are some very gentle rides at the parks especially at the Magic Kingdom.
Once upon a time, Guests were required to purchase a ticket for each attraction. I still have some E tickets which include the most popular attractions. Things have changed a lot at Disney over the years. Now admission to the theme parks include an unlimited use of the rides so you won't need separate tickets for each ride; however, everyone will be required to purchase a ticket to enter the parks.
I recently assisted another guest regarding information on wheelchairs at Disney World, click
here. You may also benefit from a Guest Assistance Card - click
here for more information on that.
Let me know if I can be of further assistance. Wishing you many magical memories :-) Allison