Are the puppies feeding ok? The nipples should not be sore so soon after whelping, but will be enlarged as the puppies suckle and the more they do the more the milk comes down. If the pups are feeding ok and not crying a lot then all should be ok. If they start to cry and keep pushing at mum and she is not letting them feed then you may need to bottle feed but it is an acquired skill - do you have contact with her breeder?