In "I Always Thought I Was the Ugly Sister Until the 9th Grade," a girl struggles with insecurity, feeling overshadowed by her more attractive sibling throughout her early school years. However, everything changes in 9th grade when she begins to blossom, gaining confidence through new friendships and self-discovery. As she learns to appreciate her own unique qualities, she realizes that true beauty comes from within. Ultimately, the story highlights themes of self-acceptance and identity, transforming her relationship with herself and her sister as she embraces her individuality.