Answer: The narrator’s struggle with trying to fit in.
Step-by-step explanation:
As she explains this, it shows that middle school was tough for her. She even said it herself. To break it down further for readers to understand, she even gave an example when she said:
"Some days, walking the halls was like trudging through peanut butter—nearly impossible."
Which is true. If you think about that statement, it makes you wonder how she even survived it because she explained how hard it was just to walk down the hallway, imagine staying through an entire class period.
"Lynette Gardner had always been my best friend, until February, when she turned thirteen. I wouldn't be thirteen until August."
Amy Bernstein managed to still have a friend until her best friend turned thirteen and most likely join the other students who already are or more. With all that said, she is trying to fit in. So, the best possible answer is the narrator’s struggle with trying to fit in.