Dragon society was very different when Sconce was young, millennia ago. Dragon parents had complete ownership over their offspring and were allowed to do almost anything to them. Parents did not lose this right until they died, their children started families of their own, their children could best them in a fight or their children were kidnapped and they were too weak to recover them. Hatchling abduction was fairly common and treated as a property crime; that is, unpunished as long as the weaker party was robbed. A young dragon running away from home was punished as a thief, as they deprived their parents of their property.  
To be fair, other societies weren’t much better at the time.
 
Dragon law has since been amended and young dragons are no longer considered belongings. But this did not happen in time for Torch’s mother, Sconce, who was given to Torch’s paternal grandfather as a belated hatchday gift and immediately passed down to Torch’s father, who was similar in age.
 
Fun fact: Torch himself had a criminal record for running away from home while it was still illegal and since a Dragon Lord cannot pardon himself, his record wasn’t expunged until Ember pardoned him.