Filmmaker and television producer Kara Kennedy, the only daughter of the late Senator Ted Kennedy, died of a heart attack on Friday at the age of 51.

She was diagnosed with lung cancer in 2003, but underwent treatment and eventually beat the disease. In 2009, she accepted a Presidential Medal of Freedom from President Obama on behalf of her then-ailing father.

She recently co-produced a film for the Edward M. Kennedy Institute for the United States Senate, and also served on the National Advisory Board of the National Organization on Fetal Alcohol Syndrome and as a director and trustee of the John F. Kennedy Library Foundation.

Kara is survived by her children, Grace and Max, her mother, Joan, and her brothers, Ted Jr. and Patrick.

A statement from the Kennedy Institute read in part, “Kara was a warm and caring person. Her children were the light and joy of her life. Her magnificent strength in her successful battle with lung cancer was a quiet inspiration to all of us and provided her family and fellow patients with hope.”