Kaya-chan Isn’t Scary - Vol. 3 Ch. 19 - "Be quiet" is not scary

[Juggernautbob]

Was that ever elaborated upon? I can't even recall anymore.

Either way, Kaya is not in the entire city all at once. She's a kid, and she solves small cases she happens to be around.
Clearly, she has no ghost-repelling aura, neither is she working 24/7 to cleanse the whole town. It's clear the author started from a small gimmick of an idea, and it happened to grow from there.

It is elaborated on in previous chapters to a certain extent. For example, mob calls her "the strongest psychic" that would only apply if she wasn't the only psychic.

Also it is elaborated even further in future chapters to an extent.

I don't really want to post spoilers for future chapters in this chapter, but she's definitely not the only psychic, not by a long shot.