I would put a pillow in my lap, and let her lay on it then put the puppy by her tit, she wants to be soothe by you, my girl still lays on my lap while her litter sleeps. just sit with her and let her relax, I sleep on a beach chair next to the whelping box for the first week.. my litter is only 3 days old.. my back suffer but my girl and her pups are happy..
