She probably ate her own stool...watch her as she plays outside and observe her often.
What Would Cause A Puppy's Vomit To Look And Smell Like Stool?
Disgusting as it is.. "Peach" is right.. It's not that unusual, especially if you're feeding her canned food
If it really does smell/look like faeces, it could be corpremesis - bringing up faeces from the duodenum. This usually indicates an intestinal blockage - your puppy may have been chewing on something she shouldn't! I would take her straight to the vet to be on the safe side - if it is an intestinal obstruction your puppy may deteriorate quickly. I would be especially concerned if she has any other clinical signs (lethargy, dehydration, loss of appetite etc.).
Let me know how she gets on!
Let me know how she gets on!