>>149197869
I think, or at most I conspiracy theory, that the original plot was that Johanna got kidnapped into a fairy mound as a kid. Astrid mentioned something like that happened but we never got to see it or hear more of it. That's why Johanna insisted from Astrid that there are no more fairy mounds in Tofoten and got super angry when she found out Astrid left one intact.

Possibly they might've said that Hilda was actually a fairy baby and not her real daughter. Not implying rape but to say the fairies literally left Johanna back on earth with an infant she adopted, as the myth goes. They reference this myth about baby snatching so many times in S3 and also in the novels but it never comes up with the actual fairies and why people keep saying they changeling babies.
It makes sense they mentioned it so many times if that was the original concept, that Hilda herself is a Fae changeling that was given to Johanna.