So great, and so true about kittens. When mamas and babies come into open intake shelters and the kittens are too young to be adopted, they are usually euthanized if they cannot find a foster.

Just a few weeks can save their lives.
I cannot foster as much because I have a formerly-feral cranky old cat who HATES kittens and wants to HURT them. This past January, someone posted TINY kittens living in a storm drain. I took them in because it was 15 degrees out and I couldn't say no.
Someone loaned me one of these and it was great for keeping them safe and keeping the mess contained. (I kept a carrier in there too so I could put them in it when I needed to clean things up every 2-3 days.) There was plenty of room for a litter box and toys, etc.
https://www.chewy.com/elitefield-2-door-soft-sided-dog-cat/dp/226670
Just in case anyone is thinking about it.