Charmian Carr, the actress who played the eldest von Trapp child, Liesl, in the classic 1965 Robert Wise musical The Sound of Music, died Saturday of complications resulting from a rare form of dementia, her family said in a statement. She was 73.

The actress was born in Chicago, Illinois, in 1942. She moved to the San Fernando Valley with her mother, vaudeville actress Rita Oehmen, and father, musician and orchestra leader Brian Farnon, at the age of 13. Carr was 21-years-old when she filmed The Sound of Music, a film adaptation of the stage production. The film, which features Carr’s notable performance of “Sixteen Going on Seventeen,” would go on to win the Academy Award for Best Picture at the 1966 Oscars.

Following her supporting role in The Sound of Music, Carr starred opposite Anthony Perkins in the TV movie Evening Primrose — her final credited screen role until her death 50 years later.

Shortly after the release of Evening Primrose, Carr left Hollywood to focus on her family; she raised two daughters while running an interior design business, through which she worked with several high profile clients, including Michael Jackson. She later wrote two books: Forever Liesl, published in 2000, chronicled her time on set filming The Sound of Music, while 2001’s Letters to Liesl focused on fan mail she’d received in the decades after the musical’s release.

Carr is survived by several brothers and sisters, two children, a niece, and four grandchildren.

Watch her performance of “Sixteen Going on Seventeen” below.