Please help me help these Moms

Hi, my name is Crisalia i am originally from SD living in PR with my husband who is stationed here. Im currently fostering 3 puppies and finding them a forever home, but as we all know, to fix this problem the moms are the ones that need to get spay. I do as much as i can to cover the medical bills which will get higher with surgeries. Anything helps, I know the animal lovers like myself will understand. Thank you in advance.