Hello Sue,
There are certainly courses on jewelry making in the Arezzo area but which one is best for your daughter will depend on how long she plans to be in Italy and whether she already has some experience in the field. Florence has a long tradition of goldsmiths and gold jewelry making and I was able to find several schools here.
For example, the Koinè Center offers a minimum of 3 month course that combines jewelry making with learning Italian. You can read more information here:
Goldsmithery Course & Italian Language in Florence,Italy
There is also the Perseo School dedicated to jewelry making. There are courses that run from 1 month to 3 or 4 months but they are quite specific on a particular aspect of the process. Read further details here:
Perseo - Firenze
Also in Florence, the Studio Arrais offers individual courses that run from 1 to 3 months. Read more at:
Studio Arrais Jewelry Design
Another gold jewelry school based in Florence, Le Arti Orafe, offers courses for foreigners, visit their website at:
Le Arti Orafe
In Arezzo, since the craft of gold jewelry is their top specialty, the schools tend to be for professionals and the courses seem to be longer in time. I was unable to find short courses but the professional school I kept finding references to is the Scuola Orafa di Arezzo. Their site, however, seems to not be currently available:
http://www.scuolaorafa.ar.it/ so it is difficult to learn more about the school.
I hope these might help you out in your search. If we can be of further help, please don't hesitate to contact us again.
Best regards