You can get supplement milk from your vet and a feeder bottle and feed it yourself. I have done this in the past. It is a big responsibility though and you have to feed it every hour or 2 just like a human baby. Good Luck!

 I have raised a very small kitten from when it was a baby. All you need to do is go to a vet that sells little bottles and get some mothers milk and put it in the bottle after it is about 10 seconds warmed up in the microwave. Try and get a little toy and a bed for it and I read in a book that if you wrape a ticking alarm clock in a blanket and put the kitten by it, the alarm clock will remind the kitten of its mother and it will calm it down and it then wont feel lonely.

 To make the kitten go potty, you have to stimulate the rear end, like a mother cat would do. With either a clean finger, or a soft wet cloth, stroke the kitten underneath the tail from the bottom up. A few strokes should get it to defecate. Hope this helps!

 Is mom on crack? The delivery truck didn't carry any maternal instincts on that trip. Hand feed the 'motherless child' with a nippled baby bottle, warmed of course and spend more time, than usual with & have more direct contact with the 'orphan'. Hold her in your hands or on your lap in a blanket for warmth. Her lack of feeding by what's her name, may well have been nothing. Keep a separate kitty litter box for baby, put her right in to it after you feed her. You can be the Mother, this animal never had, You will have to provide all the introduction and training for her life in the house, all that she is going to ever get! Good training, Mom!