How can i keep all the kittens alive? Get 10 points for best answer!!?

The mother cat is nursing them and she is doing great but how can i keep a kitten from dying. How can i Keep the mother cat healthy and keep her alive as well. My cat had 6 kittens they all are moving around a lot and nice a plump. What should i feed the mother cat to keep her healthy. Like i can't go to the vet at all i don't have the money. So What should i be feeding her. What i have been giving her is milk in the morning, i give her cat food (it says for all ages), and i make sure she has plenty of clean water, but how can i prevent a kitten from dying? I want all 6 to stay alive.