well, i'm sorry to hear that you won't be able to foster the kittens. i'm sorry i can't help out as i'm also myself short on resources. besides my 4 cats, i'm also caring for a rescued cat who has given birth to a kitten. they were rehomed about 2 months ago but unfortunately that person was a backyardbreeder. this cat ended and her kitten have ended with me again. my hands are tied not to mention $$. we're all short nowadays.
do you want to rehome them? or just foster them out? if you wish to foster them out you can try the list of volunteer fosterer available at this forum. if you want to rehome them, again you can profile them at this website. alternately, you can surrender them to spca and hope they find loving homes.
