Charmain Carr was born Charmian Anne Farnon in Chicago, Illinois, the second child of vaudeville actress Rita Oehmen and musician Brian Farnon. The couple divorced in 1957. She has two sisters, both actresses (Shannon Farnon and Darleen Carr). Her family moved to Los Angeles when she was 10. While a student at San Fernando High School, Carr was a cheerleader and played basketball and volleyball. “She had never had a singing lesson and had never tried to act” before she was signed to be in The Sound of Music. Carr was attending San Fernando Valley State College, studying speech therapy and philosophy, and working for a doctor, when her mother arranged for her to audition for a role in The Sound of Music. Rita Farnon hadn’t asked Charmian if she wanted to audition for the part, but Charmian was sure her mother would consider getting a part in a film more important than earning a college diploma. Director Robert Wise thought Farnon was too long a surname paired with Charmian Carr. After he had given her a list of single syllable surnames, she chose Carr. She won the role of Liesl over Geraldine Chaplin, Kim Darby, Patty Duke, Shelley Fabares, Teri Garr, Mia Farrow and Lesley Ann Warren. The film was on the whole a very happy experience for her. However, during the filming of her dance scene with Rolf in the gazebo, the costumers had forgotten to put no-slip pads on her shoes, she slid through a window of the gazebo, and she “had to complete the scene in agony”.

In 1965, Charmain Carr worked with Van Johnson on a pilot for a television program, Take Her, She’s Mine. Carr then appeared in Evening Primrose, a one-hour musical written by Stephen Sondheim, which aired on ABC Stage 67 in 1966. She owned and operated an interior design firm, Charmian Carr Designs, in Encino, California. Her clients included Ernest Lehman, screenwriter for The Sound of Music; Michael Jackson, who hired her because he was a fan of the film;[citation needed] and other cast members from the film. She wrote two books, Forever Liesl and Letters to Liesl. She reunited with many of her co-stars from The Sound of Music on The Oprah Winfrey Show in October 2010 to celebrate the film’s 45th anniversary. In 2014, Carr recorded “Edelweiss” with the great-grandchildren of the von Trapps on the album “Dream a Little Dream” by The von Trapps and Pink Martini. Charmain Carr married a dentist, Jay Brent, and left show business. She and Jay had two daughters, Jennifer and Emily. Later on she became the grandmother of two grandchildren: Emma and Derek.  Carr died in Los Angeles on September 17, 2016, from complications related to dementia.