It could be her own hair she is finding the food or she could be putting her own hair in the food to get free food. If the restaurant has a security camera try pointing the camera at this woman when she is eating there, then you can see whether or not she is purposely putting hair in the food. If you don't have a security camera, you or another family who is not busy in the restaurant should watch her carefully.
The worst thing that can happen if you accuse her of putting hair in the food is that you will lose an unwanted customer.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.