LitCharts assigns a color and icon to each theme in Wonder, which you can use to track the themes throughout the work.
The Difficulty of Kindness
Independence and Growing Up
Status and Bullying
Identity
Parenting and Guidance
Summary
Analysis
At the auditorium, Mrs. G directs August and Jack to their staging area. Another teacher gets them in seats and soon, Summer arrives. She's wearing a bit of makeup, and August compliments her. Jack offhandedly says that Summer looks okay, and August realizes that Jack has a crush on her. They flip through the program and Jack explains that their headmaster is long-winded. He also explains that they'll give medals to the "brainiacs" like Charlotte and Ximena. A teacher calls the kids to attention as Summer heads for her seat, and August invites Summer and Jack to his house afterward. After Sumer is gone, Jack wonders when Summer got so hot.
When Jack expresses romantic interest in Summer, it shows that he's definitely approaching puberty and sexual maturity. This reinforces that the age of Jack, Summer, and August is a major time of change for all of them, given that August is described as still looking like a child, Summer has referred to herself as "flat" (meaning flat-chested), and kids like Miles and Henry already look like teens.