Kara Kennedy, the eldest daughter of former Senator Ted Kennedy, and sister of Patrick Kennedy, died suddenly on Friday, the family confirms. She was 51. She was working out in a Washington D.C.-area gym at the time, the Associated Press reports. \"She\'s with dad,\" Patrick Kennedy said. Their father died in 2009 at age 77 after battling a brain tumor. Kara, who helped work on her father\'s senatorial campaign, was also a cancer survivor. In 2003, she had a malignant tumor removed from her lungs. According to her brother Patrick, the cancer treatment \"took quite a toll on her and weakened her physically. Her heart gave out.\" Kara is survived by her husband Michael Allen and two teenage children.