According to her memoir,  Fidel and Raúl, My Brothers: The Secret History, she spied on the Cuban administration for the American CIA.  Her code name was Donna.  

Left Cuba in 1964 to live in Miami and publicly denounced Fidel & Raul Castro as tyrons.  She had been a supporter of Fidel's revolution but was disillusioned by the executions and demise of democracy  that followed.  In a statement she said, "I cannot longer remain indifferent to what is happening in my country.  My brothers Fidel and Raúl have made it an enormous prison surrounded by water. The people are nailed to a cross of torment imposed by international communism."