I tend to keep my public-facing social medias reasonably professional, and I know some of my actual-real-life students have found my art Instagram... So I'm very careful on Instagram. I will remain so for as long as I'm a teacher.
BUT.
I make no effort to keep my Twitter kid-friendly. It mostly is, because again, professional - but I don't go out of my way to make it so. I also have a side-account on Twitter which is explicitly NSFW, and has big
NO MINORS
signs on it. My Patreon will also have NSFW sketches and such from time to time, so that will be age-restricted, too. (Not that minors tend to have the money for Patreon in the first place.)
Little kids should not be unsupervised on social sites, and teens should be told in no uncertain terms that if they are sharing space with adults, those adults are not required to cater for them. If they don't like it, they can get off those adult spaces. (Or learn how keyword and tag blocking works. It's not hard.)
I hate the idea that, just because a creator may be making a project which is all-ages friendly, that means their whole online presence needs to be sanitised. They're human, and should be able to create whatever art they like! If I want to make steamy art of the over-18 characters from my eventual YA-friendly comic for my side-Twitter or Patreon, I will be pretty pissed off if someone tries telling me that somehow perverts the comic - especially when those images are only being posted in 18+ spaces. I've done the responsible thing by curating that content in an adults-only space. It's the parent's responsibility to keep their kids off that space. Not mine.