[As someone who died protecting a teenager with no blood relationship at all, Ginia knows how strong that bond can be.]

It is. A variety of animals will go great lengths to protect their offspring or the offspring of others within the same community and humans are no different. From a purely practical standpoint, it's to ensure the survival of the next generation and thus the survival of the species. But love is a factor too, as well as need to protect those that are weaker.

In my world, people that hurt children aren't regarded very highly.