What did your dentist assess to be the high risk factors for her? How's her oral hygiene at home? Is she brushing twice a day? Using a fluoridated toothpaste? Flossing? Eating frequently can cause an increase risk in cavities. Maybe she needs to drink or rinse with water more often after eating sweets or sugar-y foods?
You are a very responsible parent. It's very good that you are concerned about your child's future dental health. Developing and maintaining good oral hygiene habits in your children plays a significant role in helping them lead a healthy life now and later as well. Discuss your child's diet with your dentist or hygienist. Besides providing hygiene instructions, they can alert you to food and beverages that can be contributing to your daughters cavities. Sometimes people are surprised to learn that many "healthy" foods and beverages can be damaging to teeth.