How old was she when she got her first vaccines? Breeders who let their puppies go too soon (before 12 weeks) also give them their vaccines too soon. Puppies get antibodies from nursing and they will block the effectiveness of vaccinations given before 9-10 weeks so they have to be repeated. Also, the last set of vaccinations needs to be given around 18 weeks full full immunity.
In one study of a cross section of different puppies the age at which they were able to respond to a vaccine and develop protection covered a wide period of time. At six weeks of age, 25% of the puppies could be immunized. At 9 weeks of age, 40% of the puppies were able to respond to the vaccine. The number increased to 60% by 16 weeks, and by 18 weeks of age, 95% of the puppies could be immunized. Parvovirus: Serious Diarrhea in Puppies & Dogs