How did Franny change in the novel, The Thing About Jellyfish?

Suzy made friends with Franny when they met each other as 5-year-olds in a swimming class. Suzy had been impressed with Franny when she first saw the girl swim underwater across the pool at their first lesson. They had been best friends since that time. Suzy had not cared that Franny was not pretty or that she was dyslexic. She didn’t care that Franny was scared to sleep at Suzy’s house during their first sleepover. She didn’t make fun of Franny when she learned Franny still drank out of a sippy cup as a six-year-old. Suzy cheered Franny up after another girl hurt Franny’s feelings. One day when the two were studying together, Franny made Suzy promise that if she ever started acting like Aubrey, one of the popular girls at school, that Suzy would send Franny a message to let her know. Once they were in middle school and Franny not only joined the popular girls but also began teasing Suzy like the popular kids did.