After looking at a variety of challenging topics — such as poverty in America, Abu Ghraib prison and illegal immigration — acclaimed documentarian Rory Kennedy took on an even tougher subject: her mother. Ethel Kennedy, the widow of Robert F. Kennedy, is not prone to introspection and has little interest in reflecting on her significant role in American history, so the 84-year-old woman is an unlikely documentary subject. Fortunately, her youngest daughter managed to convince her mother to sit in front of the cameras with her. The result is a touching and thoughtful portrait of a deeply felt, indomitable woman, who witnessed much hope and tragedy, yet emerged from this crucible with her sense of self — and humor — intact.