I wonder if there is going to be special daycare for women that don't live in human world. i don't see Asteria for exemple just give her kid to you.
Doubtful however the girls seem pretty chill about it so actually fleshing out the lore and character development doesn't seem likely.
The Artifact was a MacGuffin so Arc wouldn't have to worry about the gestation period of different fantasy races, why there could only be one pre-rendered kid but the girls could still get pregnant, and the mother being oddly calm about the entire ordeal even to the point of getting knocked up on her first time. One would think the kid would stay with the mom in the event there wasn't a place for them but no, chuck em into the void
The girls being slightly alarmed that they got impregnated by a Space Wizard Daddy might be a fun skit but no because Jedi Mind Games
I think the fan theories put more thought into this then Arc did
To actually put in depth would involve a lot more lore building then Spirited Away to the Void and the moms being as okay with that as if they had just lost a sock. Though if Arc hasn't thought of how many kids can reasonably fit in the Day Care well that could be a thing down the line.