Bay Kat, the fact that you are willing to get the kittens and mother spayed/neutered is awesome and you shouldn't have any problem getting an adoption fee to cover their surgeries.
Momma is beautiful, unfortunately I have too many dogs that already think my cats would make wonderful squeeky toys.
Whoever left you and Paso that Karma is obviously a disturbed person... While I'm quite the advocate of spay and neuter and responsible breeding (to only enhance the breed), that kind of Karma helps no one and makes no points whatsoever.
Good Luck on finding great homes and thanks again for doing the responsible thing.