"Tibby McDowell's Friends" refers to the group of characters from the novel "The Sisterhood of the Traveling Pants" by Ann Brashares. Tibby is one of four main characters, alongside Lena Kaligaris, Carmen Lowell, and Bridget Vreeland. Each girl has her own unique personality and struggles, but they share a deep bond of friendship. In the story, Tibby is known for her artistic and somewhat cynical nature. She often feels out of place and grapples with her own challenges, including her relationship with her family. The friends support each other through various life experiences, showcasing the importance of friendship and understanding.