Found family is definitely a theme running through my book series, Legend of Ahya. We have two people, marred by childhood trauma. Moira, with her abusive and molesting father, and Achenar, with his negligent parents and older brothers who kept on the wrong side of the law out on the harsh streets. Both were ultimately left abandoned and sold into the Arbiter's Project Iapyx where they were pulsed with his DNA ray to gain powers so they could be trained as child soldiers in the looming war against Talkar.
This shared trauma bonded these two together and when they were rescued by Steven, Max and the others, they clung to each other as the only familiar presence in a sea of strangers. They later found and met the former chief of the Zabokar police, Harold Bremingham, and were taken under his wing. There they agreed to be adopted by him, the black bear having lost his family in the destruction of Zabokar, and became his new children.
They were inseparable as siblings. Although Moira resisted Harold's stern parenting, Achenar thrived and became that model son that Harold never had. Still, you can take the boy from the streets, but you can't take the streets out of the boy. He rough-housed, teased and jested with Moira any chance he got, treating her like a younger brother of his with all the street smarts he had to impart onto her. This had the unintentional side effect of enabling her teenage rebellious phase, a bit later than usual, but still present - which frustrated Harold to no end. They wouldn't have it any other way - they were bound by law, family and shared pain. They were siblings.
