I have an appointment at the Humane Society this morning, and it's tearing me up to take them there. But your words are giving me the courage to go through with it. Another rescuer who makes a career out of trapping cats says that she takes all her kittens there. She says they'll call you if for some reason the cat can't be or isn't adopted, and that makes me feel better. I just wanted the kitties to go to another home, not a cage.
I do work with another rescue group, and they've given these guys space on their website and at their Adoption Days, but we don't have a building; each foster decides how many cats s/he can handle--and I'm way over my (and my family's) boundary with the sudden addition of 4 more.
Our local shelter is now no-kill, and they have another group that works with them to take the kinds of not-immediately-adoptable pets, but they're both already overcrowded, just at the start of kitten season. I feel better about AHS, for no real discernible reason, other than my memories of the shelter when it wasn't no-kill, and I was rescuing more cats than I could handle just so they wouldn't be killed.
Thanks for all the kind words and advice. As I said, they're all bolstering me to do what's best for these wonderful guys, who had real bad luck with their first "owner."