Her dad sounds like a naive know it all. I have run into a lot of people that act the way he does. It’s almost impossible to change their skepticism. She is going to have to stand up to her father and insist on seeing a doctor. If he won’t allow it then if you don’t mind making things messy she can go to her school counselor again and ask family services to help. She has rights and deserves medical treatment just like everyone else. This sounds very sticky and I commend you for wanting to get her help. I know I wasn’t any help but I do wish you all the luck.