Honestly, there’s tons of places to find someone for them. The best pieces of advice I can give you is find someone who understands (or wants to understand) the artist’s community, tactics of social and how to best optimize their systems (ie how to get their community members to where they need to go to buy some of their art, info for shows, “deeper” experiences like email marketing, etc). Most artists don’t need help with “the content” even though they will likely run into a lot of people talking about ONLY that (although maybe they do need help with content -shrug- dunno).
One of the best things I did (do) for my bestie (she’s an artist as well) is push her to look at other ways to monetize (she’s done plushies and jewelry now sold out all of her limited additions). Ensuring that the artist doesn’t feel “trapped” in their art and forcing them into a typical marketing practices/bubbles.
Find someone who wants to support the artist and the art. Someone who can speak the same “language” as the artist.