In the scene where members of the Kennedy family are watching a fictionalized Joan Kennedy speaking in Berlin, the real Joan Kennedy appears on the left on the TV screen.
Marilyn Monroe's Bob Mackey dress she wore in 1962 to sing Happy Birthday Mr President was so tight she had to be sewn into it. She chose to wear nothing underneath. She was found dead 3 months later.
Jackie's bloodstained pink Chanel suit and bag are held in the US National Archives and are not to be displayed until 2103 to not distress the family. Her hat and gloves got misplaced in the aftermath.