I'd suggest checking out both Brightlocal and Whitespark's offerings. They both offer free trials. While we've been planning on trying out Whitespark's ranking and grid software, we've been a long-time Brightlocal subscriber and track our client's branded search terms (when appropriate) along with non-branded and competitor brands on GPB/GMB and local organic. Both companies are also active on this forum in providing their knowledge and expertise. I'm sure that @whitespark (Darren) and @Jenny_BrightLocal would be happy to assist you further if you've got any other questions.
Just run Google Ads on this GBP for a month. Then look at the Search Terms report provided by Google Ads. If you are familiar with the nature of this business, you will be able to easily differentiate between a branded and non-branded search term.
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.