I am seven and a girl, and Edgars Kleppers is a silly, stupid ballerino in shiny warm-up pants and purple sweatbands—but Edgars has a beautiful sister.
This sentence adds a visualization of how the author feels and lets readers see through the characters eyes. This also embodies one of the smaller conflicts in the passage - the author's disregard for Edgars Kleppers. It also introduces the character's fascination for his sister, Diana.