Sorry about your little puppy
, sometimes the mum will reject one of a litter because there is a problem with it & it is highly unlikely it will survive at all. As far as the mum is concerned, feeding healthy pups with a greater chance of survival is a better investment of her energy. I know this sounds harsh but it's just how it goes sometimes.
Well done to you for looking out for your dog even if your parents won't get her neutered
