You could try giving her Pepcid about 30 minutes before you offer her food. I would try the Pepcid three times a day for a while and see if it helps.
Some foods to try;
Baked chicken, remove skin and fat and just shred with your fingers.
Boiled ground round, drain liquid.
Very tender roast beef.
Vanilla yogurt and Rice Krispies.
Meat loaf (no onions) meat, eggs, oatmeal, a little tomato sauce, bake.
Cook macaroni from Kraft mac & cheese, drain then mix the powdered cheese, no butter.