I'd have had my vet scan her by now

i wouldn't have thought the pups are takeing the food at only 4 weeks post mating (help me out here breeders LOL ) I would get a scan done to rule it in or out ...i wouldn't force any dog to eat she may be having a bad time with hormaones after her season ... I would be concerned if a bitch wasn't eating at say 7 or 8 weeks pregnant as then the pups would need the goodness from her

i am sure jazzy stopped eating about 3-4 weeks post mating, and didnt start eating properly again until about 2 weeks before the pups arrived. She didnt 'look' in pup til about 2 weeks before she had them, i personally would just sit tight or get her scanned. ( scanned preferably )