Obviously the child. Not as I wouldn't care about the puppies, but I am human and as a human I have to protect my species first. Yet again, considerations like "we'll disappear and nothing will happen!" are totally flawed, and this is something we share with all living things, we are built by Evolution, God or both to seek survival and to follow our instincts to the benefit of the human species as a whole. However, since the main thing which sets us apart from the rest of the animals is our reason, our reason can sometimes conflict or twist our instincts. This is why we wage wars, which are an elaborated twisted deformation of our apelike hierarchical and territorial instinct, why we smoke or take drugs, although we know they are harmful, because they trigger our pleasure forming chemical mechanisms, and this is why some of us become vegans, because humans have the unique ability to take control over their instincts through their reason and suppress them, although on the long run in the particular case of veganism this is yet again a harmful choice people can take.
Although Thomas Edison was not a doctor and it is now, 100 years later, obvious that one cannot cure everything just through nutrition, I agree with you nutrition is very important. However, we can only agree to disagree on veganism, as you keep believing- probably until you will be found with bad anemia, or with fertility issues- veganism is a healthy habit, as I am 100% convinced that humans, like all animals, should eat what they are biologically suited to eat.