When planning your story, ask yourself, What is the character arc?
To define the arc, think of the state of mind that the character is in at the beginning of the book and their state of mind at the end. Often it is from a "negative" state to a "positive" state (i.e. fearful to brave, isolated to connected, selfish to loving) unless you are writing a tragedy. Think of your book as a series of scenes of conflict between the main character and the antagonists that push the main character toward the culmination of their arc.
To tie the arc to previous questions ask yourself, How does the central gift help the character reach the culmination of their arc?
Often the "flaw" shows up at the opening of the book and in the beginning of the arc. How does overcoming the flaw help the character reach the culmination of the arc?
Following a character's arc is important because it provides a reader with a template for what to do or not do in dangerous situations.
For Scout, the arc can be defined as going from a somewhat prejudiced child to becoming a wiser, compassionate young woman (a classic coming of age arc.) Her strength serves her well here. Her love and loyalty to her family (as well as Atticus’ teachings and the circumstances she faces) help her fully open her heart to others and see the truth about Boo Radley.