Google is your friend, use the keywords "école d'émaillage".
There are probably others, maybe among the schools of applied arts such as in La Chaux-de-Fonds.
As you can see there is some choice, but a knowledge of French will be necessary.
If she doesn't want to go through a school it will be much more difficult, personal contact is the only possibility then.
Wishing good luck and much success.
Don
This message has been edited by DonCorson on 2016-01-16 12:19:54