What is the importance of Ellie's middle school in the novel, The Fourteenth Goldfish?

A lot of the novel takes place at Ellie's middle school. This setting is important because it represents several things. First of all, it is an institutional place children must go to because of their age. When they enter, they leave their old comfortable life and mix with people they don't know. Momo, Raj, and the girls who pretend to be twins, but aren't, are examples of the new people Ellie meets.

But Brianna is there as well as the new friends she makes and the fact that the two worlds coexist, Ellie's best friend for forever who is drifting away and her new acquaintances who later become her friends, plus Melvin, makes this setting significant as a conduit of change. Readers see Ellie's transition taking place in the lunch court which is a natural place for Brianna, Momo, Melvin, and Raj to be in the same place at the same time as they all don't have the same classes. The lunch court itself is special because it is outside, in nature. This fact is significant because change is inherent in the cycle of life (one of the novel's themes) and Ellie and Melvin experience change in this setting. Melvin learns to accept Raj and Ellie makes new friends and learns to embrace change.

The classroom serves as a setting for Ellie's blossoming relationship with Momo. At first Ellie is standoffish. Momo is her new science lab partner but she went to a different elementary school. When Ellie goes into the lunch court at the beginning of the year, she sees an empty seat next to Momo, but chooses to sit next to Brianna. Towards the end of the novel, She and Momo are hanging out together and Ellie says that she's happy to spend time with another girl again.