Lee graduated from Columbia University School of the Arts' Film Program with an MFA in film in 2005. While at Columbia, she won several awards for excellence in screenwriting and gave birth to her daughter, Agatha Lee Monn. Her script for The Round Up was a quarter-finalist in the Nicholl Fellowships in Screenwriting competition in 2009 and was subsequently optioned by Appian Way Productions. In March 2011, Phil Johnston, a former classmate at Columbia, called Lee to ask her to join him at Disney Animation in Burbank to help him write Wreck-It Ralph. What was supposed to be a temporary eight-week writing gig eventually turned into a much longer commitment. First, she was asked to stay on until Ralph was finished. She then became involved with Frozen, initially as screenwriter and later as co-director with Chris Buck. When Lee was brought on board, she helped transition the film from an action-adventure to "more musical, with more comedy." She worked closely with the songwriters in the writing of the script. Frozen gave her the opportunity to celebrate "wild and wonderful" girls like her childhood self, and her daughter, Agatha. It was also the highest-earning film with a female director in terms of domestic earnings, until surpassed by Warner Bros.' Wonder Woman. On May 17, 2014, Lee delivered the commencement address to the class of 2014 at her alma mater, the University of New Hampshire. She revealed that she had struggled with self-doubt while growing up, and then in April of her junior year of college, her boyfriend was killed in a boating accident, after which she felt "no doubt, only grief... and for a brief moment... better than to waste a second doubting." Years later, that memory would help her overcome her initial doubt over whether she was good enough to apply to Columbia. At Columbia, Johnston recognized she was talented but insecure, and one day asked her to "promise... that you'll leave it out of your work, just know that you're good enough and move on." She concluded: "If I learned one thing it is that self-doubt is one of the most destructive forces. It makes you defensive instead of open, reactive instead of active. Self-doubt is consuming and cruel and my hope today is that we can all collectively agree to ban it... Please know, from here on out, you are enough and dare I say, more than enough." UNH then awarded her the honorary degree of Doctor of Humane Letters. In September 2014, it was announced that Lee and Buck would co-direct a short film featuring the Frozen characters called Frozen Fever. It was released in March 2015. Lee was one of several Disney writers and directors who received credit for "Creative Leadership" on the 2014 filmBig Hero 6 and the 2016 film Moana, and received screen credit as one of the writers who developed the story for the 2016 film Zootopia. In August 2014, Variety reported that Lee's next project after Frozen would be an adaptation of Madeleine L'Engle's 1962 novel A Wrinkle in Time. After the news broke, Lee tweeted: "Been in love with the book for over 30 years. Writing this script means the world to me." Catherine Hand, the executive producer of the 2003 television film version, and Jim Whitaker produced for Disney, and Ava DuVernay directed the film, based on Lee's script. A Wrinkle in Time was released in March 2018. On March 12, 2015, Disney announced that Lee and Buck would co-direct a full length sequel to Frozen. In June 2018, Lee was named the chief creative officer of Walt Disney Animation Studios, following John Lasseter's departure from Disney.
