In chapter five Kevin calls Leo and tells him to hurry up and join him at the football game. Stargirl was on the field in a long yellow dress, marching and jumping around the cheerleaders. Normally, their tiny band and few cheerleaders received little feedback from the equally small crowd. After they performed their halftime routine, Stargirl continued twirling, then joined the players for warm ups, then grabbed the ball and punted it before running out of the stadium. Everyone cheered. The cheerleaders, encouraged by the noise, did some routines, and the next day everyone was talking about it.

At the next home game, a large crowd gathered to see what would happen, but Stargirl never came. The following Monday Mallory Stillwell, captain of the cheerleaders, sat by Stargirl, and people soon learned that she had recruited her for the squad. They spent two weeks practicing, and even though she was behaving more like the rest of the student body, Stargirl continued to hand out candies to people in her homeroom and sing to people in the lunchroom.

Chapter six begins with Hillari Kimble warning Stargirl that she should not sing to her the next day even though it's Hillari's birthday. The next day in the lunchroom, Stargirl sang the song with Hillari's name, but she sang it to Leo. At the end Kevin asked her why she picked Leo, and she said she thought he was cute. Kevin said they needed to talk to Archie.

In chapter seven they visit the home of Archie Brubaker, a retired paleontologist with a house full of bones. He lived alone with a large cactus, named Senior Saguaro, in his backyard. Archie enjoyed having students come talk to him and formed a club called the Loyal Order of the Stone with each member received a necklace with a fossil on it. Kevin and Leo visit him and discuss Stargirl. Archie knows her already as he helped homeschool her for the past few years. When they ask about her name, Archie tells them she picked it because she changes it whenever she feels like it. Her mother makes costumes for movies, and her father, like many in town, works at MicaTronics. She moved to Arizona from Minnesota. Archie answers some of their questions in riddles, so that's about all the information that they can learn about her.

Chapter eight describes how by December Stargirl had become the most popular girl in school. She performed at all the games with the cheerleaders. After Hillari's birthday, Hillari grabbed Cinnamon the rat from Stargirl's bag and threatened to drop him off the balcony to the stairwell. Then at the last moment, she pulled him in and dropped him at her feet instead. Dori Dilson, a freshmen, had started eating lunch at Stargirl's table, which opened the door for other students to do the same. People showed their appreciation by imitating her, carrying around ukuleles or putting vases of flowers on their desks.

Stargirl entered the annual oratorical contest with a speech entitled "Elf Owl, Call Me by My First Name." Stargirl won, which meant she would go on to the district competition in Red Rock, and everyone cheered.