
Two of my girls stop eating when 3 weeks in whelp and don't start again until after they've whelped. I was really worried about them, but my vet said to make sure she has food down over night as this is the time they normally start to eat, but no, neither would eat a thing.
They both went on to have healthy litters of 7 & 8 pups, as your girl is so close to whelping I shouldn't worry too much, she's feeling very full,and as long as she's ok in herself just keep an eye on her, not much longer now.