Hi Charles,
I'm not sure which
Resort category you are considering, but you can request a ground level room in most of the resorts. The Deluxe Resorts that come to mind right away as great options would be the Yacht and Beach Clubs, the Boardwalk Inn, the Polynesian and the Grand Floridian.
All of the Moderate Resorts would be great options as well. I personally would recommend the Port Orleans French Quarter. Likewise, all of the Value Resorts have first floor rooms available.
When you make a reservation, be sure to note your request for ground level. You can then contact the resort directly 9 days prior to your arrival to reiterate your request. Simply explain to them that your wife does not like elevators and prefers to stay on solid ground. Disney is great about requests and they do their best to accommodate them based on availability.
As you start browsing the vary Resorts, feel free to ask me specific questions about them if you need help narrowing your choices down further.
Have a wonderful vacation,
Kaylene