Sarcastic and judgmental, Tibby approaches her summer at Wallman’s as she approaches life in general: she expects to be miserable, and she assumes everyone around her is ridiculous. Tibby has a nose ring and former-hippie parents, and she views the world through skeptical, wary eyes. She has always had a unique outlook on life, especially since she attends an “alternative” school and has been with her parents through various careers, including organic farming. Tibby’s wariness and skepticism don’t stop her from being a loyal, devoted friend. She loves her friends and is a source of stability for them. They rely on her to take their side no matter what, and Tibby proves infinitely willing to condemn the whole world if it’ll make her friends feel better. She may judge others harshly, but she never judges her friends—no matter what they do. Although Tibby is disappointed to spend the summer alone in Bethesda, she doesn’t just sit around moping. Instead, she turns her experiences into art by making a documentary in which she records the perceived utter boredom and inanity of her hometown.
When Tibby meets Bailey, she looks no further than Bailey’s very young age and annoying persistence, certain that Bailey is just a pest to be ignored and tossed aside. However, Tibby’s usual dismissiveness is challenged when she finds out that Bailey has cancer. Tibby eventually opens up to Bailey, finding a true friend. She realizes that Bailey has a lot to teach her about compassion, openness, and happiness, and she learns from Bailey how to see what’s inside of people who may, on the outside, look like losers or fools. Tibby ultimately gains a new perspective on life, and she is more willing to live her life fully, opening herself up to others in a way she hasn’t done before.