So, how did Rory filter out everything previously said by historians, authors and journalists to focus on her own truth in making this film?
"Part of it was just the simple decision to interview my mother and my siblings and have my voice in there as the narrator," Rory told United Press International in a phone interview this week.
"Obviously, there have been a number of documentaries and books and other media about my family and I felt like what I could offer, what hasn't been in the mix before, is the perspective from inside my family, so that was part of the decision to just interview my siblings. Obviously, I had access to other family members as well as so-called experts on some of these historical events, but I felt like that had been done and can be done by others and what I could add was an inside-out perspective."
Asked if she had always wanted to tell her mother's story on film, Rory replied: "No! I've always wanted not to do this.
"I make documentaries because I'm interested in exploring the world outside of my own and understanding how other people live ... . I'm kind of less interested in exploring my own world," said the director of "American Hollow," "Pandemic: Facing AIDS," "A Boy's Life," "Ghosts of Abu Ghraib" and "Thank You Mr. President: Helen Thomas at the White House."
"There's a lot that's been done about my family and I think, as a whole, we're not an over-sharing bunch and so it wasn't comfortable for me to tell my mother's story and know I would have to ask my mother and siblings some hard questions about some very sad times," said Rory, who was born six months after her father was assassinated in Los Angeles during his campaign for the 1968 Democratic presidential nomination. "It's not something any of us are particularly inclined to talk about or explore publicly, so that was not comfortable for me."
Rory said she relented after HBO continuously pressed her to make a film about her mother, a feisty, fun-loving tower of strength. A devout Catholic and mother of 11 children, Ethel tirelessly supported the political campaigns of both her attorney general-senator-presidential candidate husband, and her brother-in-law, President John F. Kennedy -- and then continued the leaders' humanitarian efforts after they were assassinated, while also instilling in the next generation of Kennedys the vital importance of family and service.
"My siblings and I had been encouraging my mother to write a book about her life because she is such an extraordinary character and she lived through so many amazing times in our history and her story hasn't really been told," Rory said. "She has never done an interview about her whole life or a book about it, so I felt like it's a story that should be told and probably if I didn't do it, it wouldn't happen. And so I was compelled to do it."
Rory said Ethel, now 84, has seen the film and understands why it was made, but still doesn't seem to accept what a tremendous impact she has had on so many people's lives.
"She cannot see it even today. It's pretty amazing," her daughter said.
"I think her first time watching ['Ethel'] was hard mostly because she was self-conscious watching herself like any of us would be watching ourselves on television," Rory said of her mother. "But I think she appreciates the film and appreciates I did it and she's very positive about it."
One of the most fascinating aspects of the documentary is it shows how Ethel maintains her strong faith and love of life despite the early deaths of her parents, husband and two sons.
"I think it's really her nature and she does have such a natural love of life and people and she has such a competitive drive, but it's really a drive to keep going and to make the most of every moment," Rory said. "And I think, also, religion really had a big impact on her and gave her tools to get through difficult times."
Helping flesh out the portrait of Ethel in the documentary are several of Rory's siblings.
"I'm the youngest of 11, so my older siblings -- Kathleen, Joe and Bobby -- had very different experiences growing up than Chris, Max, Douglas and I, who are on the younger end of the spectrum. For example, my older siblings have direct memories of the Cuban Missile Crisis whereas my younger siblings weren't even born then or were too young to remember," RFK's youngest child said. "So, there were a lot of perspectives and mostly dictated by age."
While much has been said in the past about her father's words and actions during those turbulent times in our nation's history, Rory said her family's experiences during that era have not been fully explored until now.
"To be able to kind of step back from his perspective and look at 'What was it like for my mother? What was it like for my siblings to live through that time? What kind of choices were available to them?'" Rory said, referring to the Cuban Missile Crisis of 1962. "They had the option to leave and go to a safe place and they decided to stay and what was that like? And looking at it from a slightly different perspective for me was unique and with new knowledge was kind of an interesting way to think about it.
"I had always read about my father standing up to (Teamsters Union President) Jimmy Hoffa and showing such courage and it was a very difficult time. But what was it like ... my mother was being threatened, her life was being threatened and her children were being threatened. What was it like for them to live during those times? To kind of get that perspective, as well, I hope, adds something new to the mix."
While Rory expects the film to be embraced by older viewers who might remember her father and his contributions firsthand, she said she also hopes it will teach young people about her family's efforts to make the country a better place and inspire them to try to do the same.
"It's great to show it to older people because I think it speaks to them on a very personal level and I think so many people went through what our family went through at the same time and through these same events and so it speaks to them on a very personal level, but it's really exciting for me to show it to younger people, many of whom have very little exposure and knowledge of this time in our nation's history and certainly don't feel connected to it and I think because it is a personal story, it doesn't feel like spinach. It feels like you can feel emotionally connected to it. Young kids come out of it and they're really jazzed by it and feel like they want to learn more about this history. Also, I've heard so many people say, 'I want to give back.' Or, 'I want to commit myself to community service.' And also, 'For the first time, I can see how politics can make a difference and how leadership plays such a huge role.'"
"Ethel" premieres Thursday on HBO.