It sounds like she may have metritis, which is a medical emergency that causes sepsis and possibly death. She needs to be seen at the vet immediately!!!!!!
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Please let us know what the vet says and how she is doing. Glad the puppies are doing well so far, but I would look into feeding alternatives because I am concerned your little mama will be staying at the vet on IV antibiotics...good luck and hoping she does well. Please post updates!