“It’s not the first time that they did it, nor is it the first time I have suffered,” she said. “When he fell ill 10 years or so ago, I had my business, and they practically lynched me there, because I said I didn’t rejoice in anyone’s sickness, in anyone’s misfortunes, nor in anyone’s death. That’s not Christian. It’s not humane.”Ms. Castro said she learned of her brother’s death in a phone call from a friend. She was awake at the time and could not sleep afterward because the phone kept ringing. “I didn’t know where to hide the phone,” she said.She called her sister Enma in Mexico, hoping to get more information, but her sister had few additional details. She heard, but has not been able to confirm, that her brother had a heart attack.Although she has not set foot in Cuba in more than five decades, she was clearly up on the latest intrigue and details. She described the photos of a weakened Fidel she saw from his 90th birthday party in August, which her sister attended. Ms. Castro noted with a tinge of concern how someone had to help him get up.Like many Cubans, Ms. Castro initially supported her brother’s vision of social justice for the island nation. And like hundreds of thousands of Cubans who eventually fled, she grew disillusioned when Mr. Castro declared himself a Communist.Her last few years in Cuba were spent helping other people sneak out of the country and clashing with her brother and members of his inner circle. The two exchanged harsh words as she grew increasingly vocal, particularly when people she cared about found themselves arbitrarily detained.They barely exchanged glances at their mother’s funeral in 1963, and she decided to leave soon after when she was detained by a military official, who berated her at a bowling alley for smoking Chesterfields, an American brand of cigarettes.Her brother’s rhetoric, she had concluded, amounted to cheap slogans.