No, I have not yet seen that documentary, but I really want to see that and the Ethel Kennedy documentary (I think they are both on HBO, correct?).
Knowing the story, however, I can only imagine how sad it is. I’ve always found it poignant that George W. Bush — who I believe was about 7 years old when his sister Robin died — supposedly tried to make his devastated mother laugh and smile in the months after Robin died because he realized that she was sad. I wish I remember the exact details of what he would do, but I recall Barbara Bush mentioning it in an interview.