I didn't have an anchor anywhere," Johnson recalled. At an early age, Johnson was diagnosed with hyperactivity (ADHD) and changed schools seven times. She attended the Santa Catalina School in Monterey, California, for her freshman year of high school before transferring to New Roads School in Santa Monica, California. Johnson became interested in modeling at age 12 after a photo shoot with children of other celebrities for "Teen Vogue", and subsequently earned an income modeling while attending high school in Santa Monica. Johnson has said that she was interested in acting as a child, having spent significant time on film sets with her parents, but that they discouraged her from pursuing it until she finished high school. After high school, she applied to the Juilliard School in New York City, but was not accepted after she covered a Radiohead song. In 1999, Johnson made her film debut in "Crazy in Alabama" where she and her sister Stella Banderas played daughters to their real-life mother, Melanie Griffith. The film was directed by her then-stepfather, Antonio Banderas. In 2006, she was chosen as Miss Golden Globe 2006, where she served as the first second-generation Miss Golden Globe in the Globes' history. In 2006, Johnson signed with IMG Models. Though acting is her primary work, she has since modeled for MANGO brand's jeans line in 2009 and shot the "Rising Star" campaign for Australian fashion label Wish in 2011. Once Johnson graduated from high school, she took acting classes with teacher Tom Todoroff until 2008. She signed with the William Morris Agency and started her acting career. She appeared in a minor role as Amelia Ritter in the Oscar-nominated hit film "The Social Network" (2010), directed by David Fincher. She had a small role in the fantasy film "Beastly" (2011), followed by So Yong Kim's drama "For Ellen" (2012) opposite Paul Dano and Jon Heder, about a struggling musician in the midst of a custody battle. Also in 2012, she had roles in Christopher Neil's independent comedy "Goats", portraying a student at a prep school; Nicholas Stoller's romantic comedy "The Five-Year Engagement"; and the comedy "21 Jump Street". She also played the female lead in Chris Nelson's film "Date and Switch" written by Alan Yang. In March 2012, Johnson was cast as Kate in the Fox comedy series "Ben and Kate", marking her television debut. The show was cancelled on January 25, 2013 after one season.