How to promote fine jewelry brand?

Hi! First time poster here because my mom's starting her own brand. I don't know much about jewelry (I'm not even a jewelry girlie myself) but what would usually attract you to a non-big-branded, boutique jewelry brand? What are some ways to promote it?

We're working with sterling silver but the stones aren't actually rare stones (idk if that disqualifies us from being considered "fine jewelry" hahah), so she's thinking of marketing it towards middle-high-end for women who have a lot of occasions to wear jewelry that have high quality but also aren't insanely experience. Current pricing is around CA$150~$250 across items. She's not really willing to go on sale as it'll make her look "cheap" (missing out on the biggest marketing tactic if you ask me).

In addition, any advice for online/offline marketing? Instagram promotions? Market research? Anything would be helpful!

Thanks!