Hi Mary,
There is not really a right or wrong answer to your question, but I can offer you some opinions on which accommodations I think might work best for your traveling party!
Since you mention that you have a child who is a picky eater, I lean toward
The Cabins at Disney's Fort Wilderness Resort. I love this rustic and relaxing resort. The cabins feature a kitchen with a refrigerator, dishwasher, two counter-top burners, and a convection microwave oven. By bringing groceries, or ordering from a source such as gardengrocer.com, you can prepare some food in your cabin that will hopefully help your picky eater.
The kitchen at the Cabins at Disney's Fort Wilderness Resort is likely an advantage for you if you were considering a traditional hotel room at Disney's Contemporary Resort or Disney's Animal Kingdom Lodge. Both of these resorts; however, have a
deluxe villa portion. If you were to stay at one of these, which would be Bay Lake Tower at Disney's Contemporary Resort or Disney's Animal Kingdom Villas - Kidani Village or Jambo House, you could also book a one-bedroom or larger villa, which would include a full kitchen. At Disney's All-Star Music Resort, you may be considering a family suite; however, these have kitchenettes, which are smaller than full kitchens.
If you are not interested in preparing any food at your resort, Disney's Contemporary Resort would likely be your best bet, as it has quick and easy access to other resorts along the monorail, thereby offering many close dining options. I love the dining options at Disney's Animal Kingdom Lodge; however, they can be a bit more exotic.
I would love to help you plan more Mary; however, I am limited in the space that I have to answer. Please do write back if you have any further questions!