But she's a fan of J. Crew, we do know that. Here's a lovely (large) brooch you could easily use to gussy up an ordinary dress or blouse/cardi combo, as we've seen her do so often on the campaign trail.
Want to go a step further? Search for "paste" brooches on eBay or online in general. (Eisenberg ice is particularly lovely and desirable — just be careful to keep the look current, not costumey.)