I bred Labs, had to try and resussitate one at the breeders.. It isnt always easy. Losing a whole litter must have been tough!
I would suggest making a whelping box. There is a rim around the bottom so that if she does lean on them then she will be away from the edge giving the babies room in case she lays on them. I will be up near you the weekend of the 20th, I have to go back and look when she is due but I am only a phone call away even if I am home. I would come sit with you through it.
Tip: If she has to go out to the bathroom in the process, take a flashlight and follow her she could drop one while out there.
Deborah