Charcter development help

I am working on a story and one of my main characters is a fifteen year old named Karuna who has burn scars on her hands from abuse as well as scars from a car crash that killed her parents.

She hate's her scars and thinks of herself as ugly, even if this isn't true. I really want to show a lot of character development as the story progresses, but I am unsure how to do that. Since I started writing this story and it's prequel to highlight lead characters overcoming depression, anxiety, and other issues I don't want to stray too far from that but I also don't want to mirror what happened to the main character in the prequel but I want the two to be able to relate to each other in one way or another,

Right now she wears gloves to cover the places on her hands and long pants to cover the scars on her legs, she also has nightmares about the fiery car crash plus her abusive foster families and barely sleeps. She lives at a group home with five other girls her age as well as the instructor(who is the girl from the prequel), the instructor's wife and their four small children.