I'd like to suggest a lore-friendly way to accept kittens from Nestor without them being officially adopted.
I am unsure how controversial this kind of suggestion is, so please do read everything!
The reason for this suggestion is that I, and I know a good amount of other players, care about whether a cat's family tree is empty or not. It can be a bit unfortunate when you collect cats with no parents and get a kitten from Nestor that you would otherwise really love if they had just been an adult instead (yes, a kitten I got today is the reason I'm finally making this suggestion )
So, my suggestion would be an option to have the kitten be lore-only adopted by the village as a community.
What I'm picturing is, since there is so many lost kittens from Earth in the woods, villages could form "parent communities" that "adopt" kittens into their large families - but this process doesn't officially adopt them into any single family and therefore the kittens remain with "no family" purely in the game, but lore-wise they very much have oftentimes large, communal families.
If needed for the lore, there could even be a village lodge special occupation that unlocks this option.
I hope I managed to articulate this suggestion in a decent manner.
Thanks for reading and considering my suggestion!