Writing pro-mother/son incest propaganda didn't hurt Heinlein, unfortunately. Of course, that was a different era. Then again, incest between women is still seen as "hot" among a pretty large segment of the population.

I think it depends on if LKH knows about all the incest male authors have written approvingly, or at least slobberingly while pretending to disapprove. I simply don't think she has any kind of moral compass regarding her fantasy worlds at this point. If it's "edgy", she wants in on it.

I hope the fairy kids are just shipped off to live with relatives, though, and never show up in the books. It would be terribly storytelling, but preferable to anything I can imagine LKH doing with them.