My question is is this -
Heart murmur - can disappear if its a young puppy. Also how was it diagnosed? If its that bad enough that she does not want to breed that she is putting the pup in a pet home, then that is fine - however....what is she doing about the parents of this pup? Is she testing them to make sure that they are 100% sound via echo and holters???? Heart issues are majoirty genetic.
People who "seem like a very responsible owner" is 360 degree different from a 100% reponsible breeder!! and "seemed like she cared for her dogs" is again, much different than care for her dogs my health testing them, tracking health, showing, obedience and all that jazz. Anyone can be an awesome owner who cares for their pets and is responsible, but that does not classify them as the best breeder!!! - Just a thought.