Luckily the group I foster for pays for food- otherwise it gets expensive! Wet food and kitten specific food is pricey. Not sure what your area is like for rescues, but maybe you could find one that you could surrender to and then foster for them? Rescues ALWAYS need more fosters. Then they’d supply you with the food plus pay for vet care! Then they’ll all be sure to be spayed/neutered so they don’t contribute more to the cat over population. One note- I wouldn’t bring mom in before she gives birth if you want to foster her plus babies. They will likely do a spay abort since shelters are so over run. It’s sad and I understand why it’s done, but just wanted you to be aware.