One thing you might try is to shift the amount of carbohydrates in her meals toward the evening. When a person eats carbs in the morning, it sets up a pattern for the day, making your body to kick in insulin in antisipation of carbs, which then makes the person hungry. So by reducung the amount of carbohydrates you eat in the morning, it keeps the munchies away before lunch, and if you keep them (carbs) down at lunch it helps keep the appetite down at supper.

Also when you do eat carbs, try to eat a good amount of fiber with it. That has a tendency to make the carbs digest slower, almost like a natural time release.