How does Harper Lee show that Scout has a mature understanding of life at the end of the book?

I think Scout's maturity is shown by her sensitivity in the last captures. She is distraught over the Tom Robinson verdict. She grapples with the ugly side of human nature. I think the last part of the book is most telling though. Sensitivity and empathy are both traits of maturity. I love the ending of the book when Boo comes out of the shadows onto Scout's porch. There is none of her earlier childish statements or behaviors. She is not scared and, unlike many adults, does not look upon Boo as an oddity. She simple says "Hey Boo". This gentle greeting shows how sensitive Scout has become. It is friendly recognition but also has the subtext that says so much. The subtext underneath her tone speaks to Scout's feelings that she knew it all along. She may have not comprehended Boo before but somewhere under the childish stories and games, Scout was sensitive enough to realize that Boo was not a monster.