I would agree with your assessment. And, I think there's a few factors that encourage this.
1) Artistic folk tend to be more socially and sexually liberal.
2) I might even posit the idea that artists are already comfortable with the idea that one can sell very personal, vulnerable things without actually "selling" oneself or diminishing personal relationships. For example, Maggie McNeil comments that a chef can pour his heart into delighting his patrons with his meals, and still appreciate the intimacy of cooking for his partner at home. So, in addition to being more liberal, one might argue that artists are more likely to be able to put providing into the right mental framework, and be better equipped to compartmentalize.
3) Unless you have a contract to produce on schedule, artistic work is extremely flexible. In that way, providing and artistic work is one of the golden match ups. Especially if providing is your primary source of income, then you can flex your artistic pursuits around the rushes and lulls of the work.
4) Calling yourself an "artist" has no barrier to entry. Sure, some artists might have art degrees, a stack of paintings or published work, but none of that is a requirement to say "Sure, I provide, but really I'm an artist." Some of the artist providers I've met over the years legitimately do dedicate their energies toward one artistic pursuit or another. They carve out dedicated time in their day and actually have real stuff to show for it. Others have an "artistic soul"-they might take a tap dancing course, and they love to hit the art galleries, but I wouldn't call them creators. Most of this latter group likes the idea of being artistic, but is put off by the fact that creating is a whole lot more wailing and gnashing of teeth than riding glittery unicorns across the rainbow. (Which is really fine with me. No one has to be an artist, at least in my book, and/or if you're doing it for the provider branding, that's totally cool too.) Anyway, the point of #4 is simply it's a lot harder to declare yourself, say, a lawyer (which requires years of schooling and licensing) than it is an artist.
5) In my experience, mental health issues are more common in the providing population than they are in the general population. And, mental health issues seem to be more common in the artistic population than in the general population. Given that, it's not surprising you have a higher overlap.
6) Depending on what area of SW one goes into, she may find it beneficial to develop certain artsy behaviors. For example, when I returned, I knew I wanted to do all of my own photography. My best friend's girlfriend is a burlesque performer. This started her down the path of costume design that evolved into pro-design for other dancers, and she's now also getting very deep into video production due to Covid. So, pick your pursuit there. There's no lack of talented writers in the industry, either, and while I can't say whether providing inspired them to pick up the pen, I'm sure years of applying it here has improved it.