Welcome to the Disney Parks Moms Panel Ashley!
What a sweet daughter and sister you are to plan ahead for your Father and brother. My thoughts are the more I plan ahead of time, the less I'll have to worry about once I reach Disney and can relax and enjoy my trip.
Disney offers
Wheelchair Rentals for use at all four of the theme parks (Magic Kingdom, Epcot, Disney's Hollywood Studios and Animal Kingdom). Reservations are not accepted. Wheelchairs are available on a first come, first serve basis. Wheelchairs must remain in the parks in which they were rented. If you visit other parks on the same day, you'd just have to show your receipt at the next park to obtain another wheelchair.
You can purchase a Length of Stay Rental at the Wheelchair Rental Location which will save you some money by pre-paying for the number of days that you will require a wheelchair. The Length of Stay rental ticket is $10 per day when rented for multiple days (prices are always subject to change without notice). Once you've paid for the Length of Stay Rental, you'd simply show your receipt at the rental location to receive your wheelchair for the day. The Length of Stay Rental may not be available during peak seasons. It also doesn't reserve a wheelchair for you - they are always first come, first served.
If you think that you'll need use of a wheelchair outside the theme parks, there are several local companies that provide length of stay rentals. There are some listed on the link provided above including Buena Vista Scooters which will give you a discount if you mention AllEars.net when booking. These companies will deliver and pick up from your resort which makes it very convenient.
Please feel free to visit us with all your planning questions. Its our pleasure to assist you!
Wishing you minnie magical memories :-) Allison V.