How does the main character change by the end of the novel?

Lisa grows and matures far beyond her years as the story moves forward. Lisa spends her time thinking, planning, and solving problems. When she loses Glenbard to Tom Logan's attacks, she blames herself for not having the foresight to prevent Glenbard being taken from her. She feels she earned Glenbard and must continue to earn it by thinking up the ideas to protect it.