Hello! The best way is to exercise: combine treadmill ( cardio) with weightlifting. This will help ti increase her metabolism so she can burn more calories. She will gain muscle which is equal to mire fat burning. Try to eat a high protein diet with cheese, egg, cottage cheese, milk chicken, fish and less carbohydrates such as bread, rice, cookies, spaghetti, desserts, in order to fuel the muscle. It antioxidants fruits rich in vitamin A,C,E: limons, oranges, carrots, etc. Try ti eat good fats such as seeds, avocado, fish. Thank you. Best regards.