I just took my final on To kill a Mockingbird an the essay question I had to answer with two examples was why was this a comming of age novel and give two examples and a level 2 essay. this I found to be not to hard a task since it was an open book quiz.
Scout learns that it is sometimes possible to avoid fighting by simply choosing not to fight. This lesson, one of the hardest for Scout to learn in the early portions of the novel, is central to the demeanor of her father and his character.
Scout's success in becoming more like Atticus demonstrates the idea that she is beginning to come of age.
So glad you think you did well, and your job would have been easy if you saw this as Jem's coming-of-age story rather than Scout's. It is true that she is the narrator, but it is Jem who does the growing up here. Without Scout we would not have a story; without Jem we would not see how the events of the story impact and change a person.
I think the easiest way to answer this question is the framing of the story around Boo Radley, the opening and closing of the novel with two very different perspectives of this character. If you chose to cite Jem as your main example rather than Scout, I think his mid book quote, "Atticus is a gentleman, just like me," is one of the better examples of his maturity.
As children mature and are guided by good parents, they traverse new avenues of thought rather than the narrow lane of selfish ideas that a child has. Scout and Jem learn to do what Atticus Finch instructs his children; that is, to step inside the skins of others and see things from their points of view. Scout learns to respect Walter Cunningham as a person; Jem learns to perceive things from the point of view of a suffering Mrs. Dubose; he and his sister see Tom Robinson as a person; they learn to respect Boo Radley as a person. Jem and Scout Finch mature as persons; they come of age.
Well, then, I hope you aced your final. I would have probably used the examples of Scout's awakening at the end of the novel when she stands on the Radley porch; and Jem's recognition of Tom's innocence and the injustice of the verdict delivered by the jury.