Hi there Patti,
I am also a single parent, but of a 7 seven year old. My daughter and I have traveled to Walt Disney World since she was 2 years old, and almost always have stayed in one of the value resorts. The last time in August we were there and stayed at the All-Star Sports hotel (I liked it a lot because we had a preferred room and were very close to the main building (where the arcade is-ARGH!) and the food court, as well as both the pools, so not much walking was involved which was really nice (we get enough of the walking when we are in the parks all day!).
If I really had to choose one of them though to stay at next time, it would probably be at the
All-Star Music resort because my daughter really loved the theme for one thing (she is a music fanatic!) and also I think it has the best options in the food court of all of them and they had great children's activities throughout the day, both at the gift shop and at the pool (they might not have this anymore, I am not sure, you will have to check with a cast member on this) The pool by the way is filled with blow up balls for the children (and adults!!!!) to play with. Overall, I find this one the most enjoyable and the atmosphere electric.
I hope this helps you, but one last note, wherever you stay in Disney World you are bound to be surrounded with Magic. Enjoy it.