She is adorable, and I hope things work out. I agree, a trip to the vet would be well worth it, and protect the cats already in the home. Tell the vet it's a rescue, sometimes some will work with people financially in that case. Can't hurt to ask.

What I might suggest is finding a no-kill rescue group in your area. You can find them through
.
, click on shelters and rescue and put in your area and you'll get a list of all the shelters and rescue groups and ask about their putting the cat up for adoption.

More often than not, these groups have waiting lists, sometimes months long, so it will allow your son to keep the kitten for a bit to see whether he can keep it, but if he finds he can't, you're already on the list. You can always change your mind and keep it when your name comes up.

They will never destroy an animals and keep them either up for adoption for fostered until they find a good home, they are very careful.

It's sorta like having your cake and eating it too, and the kitten is ensured to always be safe and have a promising future either way.