When John Locke was writing his Treatises, he needed a way to define governmental, or political, power. He started by drawing an outline around political power by defining another kind of power, one related to the state of nature: paternal, or parental, power. In that spirit, let's try to define what kids are by, first, discussing what they aren't.
If one owns oneself, then one owns one’s body, mind, and that which one’s body produces. Meaning that life and body are sacrosanct. Here, you have the basics for non-violence and voluntaryism. All one must do to complete the voluntaryist, anarchist puzzle is see the necessary link between self-ownership and the ownership of property.