Jewelry

I have a very special ring that my father gave to my mother. It is platinum with a diamond. I don't know what the setting is. My mom loved this ring. In fact she wore it so much that the band is thin at the back. I need to find a place that can not only size it for my girl, but also beef up the band. I don't know if I should look at a place that sells diamond stud earrings or a jewelry repair place. I don't really have the funds to drop on it but I need to do something before July.