Some cats aren't naturally good mothers. She may be sick or something, and that instinct to go and hide might be why she is abandoning the litter.

If you could somehow find someone with a mother cat already nursing kittens, you might be able to foster them off. What I remember used to work was rubbing the kittens with butter. Once the new mom licks off the tasty butter, the babies smell right and she will keep them.

I hope something works out for you and them.