I'm so sorry I missed this thread.

The mother will not come back, trust me on this one. You are considered a predator to her and that is why she moved her other babies.

The only thing you can do now is concentrate on caring for the one baby left. Make calls to shelters, or rescue organizations to see if there are any lactating (nursing) mothers there. If so, ask if you can bring the kitten in to nurse off of her. She'll have a better chance.

She will let you know when she's hungry, believe me!! You got alot of great advice here. I just wish I had seen this thread sooner. Keep the heating pad on low and cover it with a towel. The kitten will sleep most of the time unless she's hungry.

One other suggestion is if you have one of those wind up alarm clocks, put that in as well, as it simulates the mother's heartbeat.

Good luck. You're doing a great thing.