Prolific production designer and art director Hardwicke made her directorial debut with the drama that depicts a contemporary mother-daughter relationship. Los Angeles teenager and overachiever Tracy (Evan Rachel Wood) is an excellent student in her seventh grade class and gets along well with her mother, Melanie (Holly Hunter). She fears that she's not cool enough to be friends with Evie (Nikki Reed), the most popular girl in school. Fueled with genuine adolescent energy, Tracy follows Evie's lead into the harsh realities of sex, drugs, and hard-edged adventure. Consumed with temptations and conflicting desires, Tracy loses her good-girl identity, greatly affecting her relationship with her mom. Partly autobiographical, "Thirteen" was co-written by Hardwicke and Reed when Reed, a close family friend, was 13-years-old. Originally intending to write a teen comedy, they ended up creating a hard-hitting drama exposing the contemporary teenage experience. The film is very much a zeitgeist for modern feminine culture, pointing out the flaws in today's society that encourage the premature sexualizing of girls.
"Thirteen" was nominated for the Grand Jury Prize at the 2003 Sundance Film Festival, with Hardwicke taking home the Director's Award. The film earned a best actress Oscar nomination for Hunter. It is described as "a wonderful testimony to getting women's voices out in culture and showing the power of a woman's point of view."