She is probably best off renting an
ECV from an off-site company. Some information for off-site rentals are:
Walker Mobility:
1-888-726-6837
www.walkermobility.com
Care Medical:
http://www.caremedicalequipment.com/
RANDY'S Mobility is in Kissimmee 407-892-4777
http://randysmobility.com/
Colonial Medical
http://www.colonialmed.com/about_cms.html
I have used Walker a few times. They will ask for a credit card and charge it the day before arrival. They will deliver the ECV to your hotel bell services before your arrival and pick it up there after your departure. Their rates, especially for longer than a week, are much better than Disney's. Also, their scooters are much better.
If she is staying at a Disney resort there should be no problem at all for transportation. The monorails, boats other than the small yachts, and almost all the buses can handle them. This will not get her to the head of lines, but she will be comfortable and will not tire out.
If she has never used an ECV, have her go to a large grocery store. They will generally have
ECVs available for their customers. Just tell her that the store ECVs are MUCH harder to use than the rentals. (The rentals are generally three wheel and much more maneuverable.)
Even at the smallest-room Disney resorts there is sufficient space to plug in the charger and park the ECV, hooked up to the charger, overnight.