You will probably find that after a couple of days she will allow you in to check on them. Don't worry too much, provided she seems to be feeding them and they are content she will know what is best for them. If they fall off the bed she will just pick them up by the scruff of the neck and return them to the nest.
I have one bitch who would never let me touch the puppies for the first couple of days, if i tried she would snatch them back from me and put herself in between me and them.
As doglady says, try feeding her outside the room, and maybe you could put her food in a cage and then close the door if she goes in it. No matter where you move the puppies to, if she is not happy with it, she will try to move them to where she wants them.