Defined by Destiny by Hermione Lee

Kathleen Bell is devastated when her boyfriend, Weston Stevenson, stands her up at Magenta High's fall dance. The next Monday, he publicly accuses her of hiding her family's history of mental illness and breaks up with her. To make matters worse, school bully Marjorie Nguyen proudly claims credit for exposing Kathleen's privacy.

A heartbroken Kathleen finds comfort in Ryan Harte, a friend she met at the dance. Bonded by their struggles, their friendship deepens into love.

With Ryan by her side, Kathleen heals. But one day, a shocking family secret turns her world upside down, forcing her to reconsider everything she knew about Marjorie, her deceased mother, and herself. As Kathleen's high school career draws to a close, she must decide whether to let go of the past or look forward and move on.