Ok, first and foremost: my current vet's associate said to express some milk from the mother's breast and then put the kitten right up to it while the milk is coming out. That should get her to eating but if that doesn't work, put some expressed milk into a dropper and feed the kitten that way. If that still doesn't work, here is the formula. My late vet's associate had it handy:

1/2 C. evaporated milk
1/2 C. water
1 egg yolk (no white)
10 drops human baby vitamins
2 T. Karo syrup

You will have to feed it w/a dropper every 4 hours around the clock and rub the area where it poops and pees w/a warm wash cloth in order to get it to go. Keep it warm but not too warm and try not to handle it too much other than for feeding. My current vet's associate said that time is of the essence; don't wait too long if you see that the kitten won't feed from her mom.

Good luck and bless you for taking care of the sweetie pies. (((HUGS)))