Milly is a wealthy 17-year-old prep school student from Manhattan, the daughter of Allison Story, and one of the three narrators and protagonists. Milly’s full name is Mildred, after her grandmother, and she believes that her mother named her this in an attempt to appease her own mother because “why else would [she] saddle a twenty-first-century girl with a name like Mildred?” (22). Milly’s father is Japanese, and her parents are divorced. Jonah describes Milly as “drop-dead gorgeous” (52) with “dark hair, dark eyes, and full lips curved in a smirk that should probably be annoying but isn’t” (53). Aubrey admires Milly’s beauty, fashion sense, and intellect, noting that Milly is usually “three steps ahead of [her]” (113) when it comes to piecing information together.

Milly, however, doesn’t see herself the same way that Jonah and Aubrey see her. She knows that she is pretty, but she has spent her entire life feeling like she isn’t good enough for her mother. She is self-conscious about her performance in school, claiming that “it’s the bane of [her] mother’s existence that [Milly] [is] always ranked solidly in the bottom half of [her] class” (16) at her elite prep school. Her mother constantly corrects her grammar, denies her physical affection or praise, and leaves Milly feeling like she will never measure up to the Story family standards.