Hi from one kittylover to another kittylover, I really dont have an answer to solve your problem only that I totally agree with the other ABer's posts in that you really should have the 3 kittens and the mother cat spayed asp. I have 2 females and 1 male all of which have been spayed and neutered, micro chipped and have up to date inoculations, not cheap if you are a true pet lover to keep them in good health.
I'm not saying you are not a true pet lover but please be a little bit more responsible in your cats welfare as I have seen too many times on T.V. on Animal Programs where owners get so over run with cats "plus" dogs that the owners think they are coping with so many pets that they end up in rehoming centres, I get so up set seeing this happen for it's heart breaking to see the owers having to chose which one to keep and who's to go, and the bewildered look on the pets face's as they are carted off, after all its not the animals fault they didn't ask to be born, pleasr, please dont put yourself in this situation. X X X :-)