In the beginning of the story Lizabeth was a small girl who loved to play and cause mischief with her friends. She also loved to mutilate the beautiful marigolds in Miss Lottie's garden because they were beautiful unlike the world around her.
In the middle, Lizabeth overhears her parents talking about all the hardships they are facing while she tries to sleep, and she sees her dad crying for the first time, and feels like her world is upside down. She is angry about everything and doesn't know how to fix their problems.
In the end Lizabeth wants to vent out her anger, and she does this by destroying the only beautiful thing in her world that doesn't fit. She destroys Miss. Lottie's marigolds. While doing this she becomes an adult and thinks about the world in a different perspective. She realizes that Miss Lottie owns those marigolds because they are the only perfect thing she has after a hard and long life.