You are under no obligation to provide medical records with respect to your four (4) year old daughter to verifiy the reasons why you are cancelling the trip you are writing about. Custom and practice in the travel business is that a letter from the treating physician explaining in general why you cannot make the trip suffices.The travel insurance company can ask for your daughter's medical records but you are under no obligation to provide such. As a parent, I would not provide my daughter's medical records to verify why the trip is being cancelled.