Where can one learn leatherworking in California?

Contact Levergun at http://www.levergunleather.com/
He started in California before he moved to Idaho. He may know someone you can contact.

Google or Bing it with the type she wishes to do. There are thousands of places in CA. Also check with your Chamber of Commerce.In addition, If she wants introductory or hobby lessons check Tandy Leather Company. And chat with the local store clerks.

@MaryW What are the different types of leatherworking?

Hobby is wallets, earrings, necklaces, belts. Commercial can be those plus English saddlery is saddles bridles driving equipment, Western saddlery, Artistic embossing can be making book and check covers, chair seats and backs, belts. There’s lots of options and those categories are loose and cross back and forth. So that is why I mentioned Tandy Leather company as they have supplies and know people who give lessons.