The Face on the Milk Carton is a 1990 novel by Caroline B. Cooney. The titular "face on the milk carton" refers to the protagonist, Janie Johnson (or Jennie Spring), a fifteen-year-old girl who is, ironically, lactose intolerant. She has a wild mane of bright red hair—which no one else in her family has—and lives a relatively protected and privileged life.
One day, however, she sees herself on the milk carton and begins wondering if her parents are truly her biological parents. She is curious and persistent as she begins to hunt for evidence about her parentage. This journey sends her on an emotional rollercoaster, and she moves through phases of distrust, wondering if her parents are actually her kidnappers; loyalty, when she grapples with protecting her parents; and uncertainty, especially when considering her romantic relationship with Reeve Shields. Janie is also brave and determined; she wants to know the truth about who she is, regardless of how painful or upsetting that truth may be.
Reeve is the "boy next door" (literally), and has been a friend of Janie's since their childhood. Two years older than Janie, Reeve has his driver's license and often drives her to school in the morning or to her house at the end of the day. Reeve finds school to be harder than Janie does; although, throughout the course of the book, he begins committing more diligently to his schoolwork and starts to address the inferiority he feels in relation to his siblings. He becomes Janie's boyfriend and supports her search to find out the truth about her past. Additionally, his sister, Lizzie, used to babysit Janie and helps Janie call her biological parents at the end of the novel.
Mr. Frank Johnson and Mrs. Miranda Johnson, as we learn by the book's end, are the parents of Janie's kidnapper—a fact that explains why they are older than the parents of Janie's friends. Their daughter, Hannah, kidnapped Janie. Mr. and Mrs. Johnson dote on Janie, loving her fiercely, and are very concerned about her safety; for example, Mrs. Johnson won't let Janie go out alone and always wants to know where Janie is and who she's with. They feel they "lost" their first daughter (Hannah) and so they guard Janie and her well-being with ferocity.
Sarah-Charlotte Sherwood is Janie's best friend. The book tells us that she's very pretty and has bright blonde hair. Like Janie, she loves talking on the phone—especially about boys, as she's looking for a steady relationship. Towards the end of the book, Sarah-Charlotte gets mad at Janie for being so involved in her search for her parents that she never has time to talk to Sarah-Charlotte on the phone anymore.
Hannah, the daughter of Mr. and Mrs. Johnson, is the person responsible for abducting Janie. Hannah joined a cult and married its leader. One day, she arrived on her parents' doorstep holding a baby and asked her parents to raise the child; she had kidnapped Janie from a shopping center.
The Springs are Janie's biological parents. When she learns who they are, she wants to get to know them, and the novel ends with her calling them.