She fled Cuba with her bourgeois family as revolution brewed, and later married into one of Europe's royal dynasties.
Today, as the Communist-ruled island emerges from long economic isolation, Luxembourg's Grand Duchess Maria Teresa says she hopes to return home to pitch the cause of micro-credit to help the country's poor.
A Unesco goodwill ambassador, Maria Teresa, 59, has long championed collateral-free seed loans to help families set up businesses to haul themselves out of poverty -- the system famously set up by Bangladeshi Nobel Peace laureate Muhammad Yunus, founder of the Grameen Bank.
She has backed projects in countries as diverse as Nepal, Mali, Thailand, Laos and Bosnia, and hopes that Cuba, too, can benefit.
"From an economic point of view, there is an enormous amount to be done for (Cuba)," the wife of Grand Duke Henri, the monarch of the tiny but wealthy EU nation, said in an interview with AFP. "(...) The Cuban population has suffered greatly for very many years."
She added: "One thing that would give me enormous pleasure would be to travel to Cuba with Professor Yunus to launch microfinance.
"It's something I feel very passionate about. I don't know if the situation economically is right or if the political opening is sufficient and ready to do it now, but it's a dream I have."
- Castro 'neither friend nor enemy' -
In 1959, Maria Teresa's family, a banking dynasty of Spanish descent called the Mestres, fled Cuba, leaving behind a business empire that would be confiscated by Fidel Castro's revolution.
The Havana-born duchess admitted it would not be easy going back to a country where Castro, 89, is still living and which is still run by his brother Raul following Castro's retirement due to ill health.
He is neither a friend nor an enemy. He is someone because of whom my whole family had to leave the island of Cuba. This is not an easy situation," she said.
However when Maria Teresa became engaged to marry Henri, then the heir to the Luxembourg throne, on November 7 1980, Fidel Castro was the first to congratulate her.
"The first bouquet that arrived at the palace was a huge bunch of roses with a card from Fidel Castro, with all his congratulations," she recalled.
Following her marriage in February 1981, and her husband's accession to the throne in October 2000, she met Castro in Havana through the efforts of a first cousin who was close to the Castro regime.
She said the opening up of Cuba and the end of the US trade embargo made her "very happy" for the Cuban population. US President Barack Obama is due to make a historic trip to Cuba on March 21-22.
"Cubans are geographically close to the United States but their heads and their hearts are turned towards Europe," the duchess said.
"They have a lot of affection for France and, I hope, a little bit for Luxembourg these days. I hope Europe will be there for Cuba at this moment of change."
- Luxembourg royals reforming -
At home, Maria Teresa said Luxembourg's famously discreet royals are undergoing a "profound reorganisation" to become more "transparent" and "authentic."
She said her husband had been through a "difficult test" when in 2008 he gave up his power to sanction laws so that he did not have to pass a law on euthanasia that he did not agree with.
But she said the monarchy still had a "very concrete role", citing Grand Duke Henri's intervention in a political crisis in 2013 after Jean-Claude Juncker -- now head of the European Commission -- was voted out of office after 19 years as Luxembourg prime minister.