What do you do if a mother cat has milk but no kittens to feed?

If the mother cat of kittens is still milking, and the kittens are under eight weeks, then you should let the kittens milk as much as they want. Depending on their age and weight, you should gradually give them more of your own water and semi-wet/dry food until they start coming to you and not 'meowmy' for food. Then they should feed completely on a human-provided diet.

If the kittens mother is still milking and the kittens are ready to move on from mom, then you should try taking the kittens away from their parent for gradual time increases.

For example:

day 1, 10 minutes

day 2, 20 minutes

day 3, 30 minutes

day 4, 1 hrs

day 5, 2 hrs

day 6, 4 hrs

day 7, 6 hrs

day 8, 9 hrs

day 9, 12 hrs

day 10, 18 hrs

day 11, 24 hrs

Hope this helps & good luck!