Switch her to 2 meals a day..and cut back on the amount. If she's eating and quitting with food left in her bowl, she's getting more then she needs. At her age, you can very safely feed morning and night feedings and not worry at all. The only thing I can think of other then that, is to soak the food with warm water until it has a 'gravy' and then feed it to her. Some dogs like their food 'fresh kill' warm.
Good Luck
