Is there any way to teach a cat how to pick up her kittens?

My mama cat did the same thing with her first litter. I asked my vet and he told me to just leave her alone and let nature do its thing. Maybe keeping her and her babies in a room just for them will ease the tension of mama and get her to relax. If she is frantically trying to get her babies back to the box or in her eyes, the safe place then she feels threatened for herself and her kittens for some reason. I hope this helps you in some way.Good luck!