Thanks for choosing Doctorspring.com I understand your concern. I have read your question with diligence. I can understand your problem.You should not worry too much at this stage. As a rule generally if a child does not have pain we do not recommend any treatment .Treatment is recommended for continuous pain or presence of severe deformity.Also best is to have treatment when she is 18 yr old & if flat foot is giving problem to her.Till then she smay use shoes with built in cushioned arch support. Some other treatments like walking on naked feet in sand near the sea or sand with large granules.This will help in increasing muscle tone & mass at her inner aspect of foot. She may also do some exercises like grasping the edge of a cloth at floor frequently with toes. Hope this will help her. Do get back to us for additional queries. 