My Horrible Year! (2001)

After her favorite uncle passes away, fifteen year old Nik feels herself trapped in the world of braces, babysitting, crushes, and suburban life until she overhears a conversation between her parents. Now Nik is convinced that her father is having an affair with her widowed aunt and that her parents are going to announce a divorce on her sixteenth birthday. Despite the reassurances from her non-conformist friends, Babyface and Mouse, that divorce is not the end of the world, Nik will try anything to keep her parents together.