My sister adopted a child with severe trauma. The kid had been in five foster homes. Abused, neglected, and angry at the world. My sister brought him home and he destroyed things, lashed out, said he hated her, and tried to run away. Everyone told her to send him back. They said he was too damaged, too broken, and that she'd taken on more than she could handle. She kept him anyway. She didn't give up when he screamed, didn't abandon him when he fought, and just loved him through the chaos. It took three years.
Three years of therapy. Three years of him testing her, trying to prove she'd eventually reject him like everyone else had. But she didn't. One day he just stopped running, stopped fighting, and stopped waiting for her to leave. He asked if he could call her mom. My sister cried and said yes. He's sixteen now. He still has hard days and still carries trauma, but he knows he's not going anywhere that someone chose him, and kept choosing him even when it was hard.