“Economic necessity has separated our family,” she said. “I want to put it back together.”

But making the 30-minute hop to Florida will not be easy for Niurka, a 45-year-old doctor, whose brother left Cuba a decade ago, followed by her father and then, five years ago, her 24-year-old son. Like all Cubans, she needs permission to leave, but as a member of the country’s medical corps, she may be forced to wait years for an exit permit — if she gets one at all.

So Niurka, who asked that her full name be withheld lest she spoil her chance of traveling, anxiously awaits a promised reform of Cuba’s migration rules that, for half a century, have controlled who can leave the island, who can return and how long they can be gone.

Any loosening of controls would be a step toward eliminating one of the most deeply resented restrictions on Cubans’ liberty and a milestone on President Raúl Castro’s gradual march toward economic and social reform. Cuban officials have hinted for years that a change might be coming, but the bureaucratic system limiting travel remains in place.

If it does become easier for Cubans to legally leave the island, the reform could spur economic migration and deepen ties between the island and the two million members of the diaspora, whose money and business experience may be vital to the government’s plans to drastically enlarge the private sector.

“If you have a significant change to the migratory law, it will be a watershed,” said Arturo López-Levy, a Cuban-born academic who left the island 10 years ago and lectures at the University of Denver.

“It could unleash the potential of the whole reform program and it could empower the actors who favor reconciliation between the Cubans on the island and the diaspora,” he said. “This is a critical juncture.”

Hundreds of thousands of Cubans have gone into exile or migrated over the past five decades, and thousands are believed to have died trying to cross the Straits of Florida in small boats — partly because American policy promises residency to Cubans who make it ashore. Though many Cubans now pay smugglers to take them to the United States via Mexico, the United States Coast Guard continues to find would-be migrants at sea.

There was a swell of hope for new travel rules last August, when Mr. Castro told Parliament that the government was working on “updating” the law.

Then in an interview published this spring, Ricardo Alarcón, president of Parliament, said the government was planning a “radical and profound” reform in the coming months. Deputy Foreign Minister Dagoberto Rodríguez said during a video conference with Cubans overseas in April that progress on the issue was “advanced.”

In lines at the migration office, on blogs and in conversations among islanders and members of the diaspora, Cubans question whether the government will part with such a lucrative bureaucracy or risk letting go health workers whose overseas missions earn Cuba billions of dollars each year.

“It’s one thing for a foreign country not to let you in and another for your own country not to let you out,” said Amparo García, a jewelry seller whose daughter, 23, is in the process of getting a permit to visit her father in Angola. “If you have the money and you want to travel, you should be able to buy a ticket and go to the airport. That simple.”

Jorge Martínez, who charges $1 to type up migration papers in the front seat of his 1969 Volkswagen Beetle, said more people than usual were applying for passports because they believe the government will scrap the exit permit and increase passport fees to make up for lost revenue.

“People have been talking about this for years, but right now there’s a lot of expectation,” he said.

Cubans and analysts said any kind of change would pique interest in travel but would be unlikely to provoke a mass exodus, because many countries restrict the number of Cubans allowed to visit by requiring them to seek a visa beforehand. The United States requires a visa for legal travel; however, Cubans who present themselves at an American border checkpoint or who manage to reach the American shoreline may stay and, after a year, seek permanent residency.

Under current rules, Cubans who wish to go abroad face a bewildering — and expensive — array of permits and provisions.

To get a Cuban exit visa, they often have to provide a letter of invitation from the country they plan to visit, pushing the cost of the whole process above $300 — a significant sum in a country where average salaries are about $20 per month.

Many Cubans obtain permission to leave in days or weeks, but the government tightly restricts travel by children, medical personnel and other professionals, as well as members of the security forces. Niurka, for example, must be “released” from duty by the Public Health Ministry before she can apply for an exit permit.

The government also frequently denies travel permits to dissidents or critics, like the activist and blogger Yoani Sánchez, who has written of being turned down 19 times.

Once overseas, Cubans must pay the nearest Cuban consulate if they stay more than 30 days. The fee is about $60 a month in Europe and $150 a month in the United States. After 11 months abroad, Cubans usually lose their rights as a citizen.

The government has hinted that it will change the 11-month rule, which would improve its relationship with Cubans abroad. Officials have softened their once-caustic language against overseas Cubans and promoted talks with them about their role in the island’s future.

Cubans living overseas, particularly in the United States, send at least $1 billion — some estimates are double that — in remittances each year. They are investing money in relatives’ businesses and, on the sly, buying houses and cars on the island.

“Today, the overwhelming majority of Cubans who emigrate do so for economic reasons,” Mr. Castro said in August.

For people like Niurka, though, the reform may bring less relief. Mr. Castro has said new rules will include “reasonable measures” to prevent a brain drain in the face of “the American government’s interventionist and subversive plans.”

Mr. Alarcón, in the interview with Salim Lamrani, a French academic, which was first published in The Huffington Post, pointed, as justification, to the United States government’s Cuban Medical Professional Parole Program, introduced in 2006, which offers a visa to any Cuban health worker who defects during a mission overseas.

Mr. López-Levy said that the Cuban government used American policy as an excuse to restrict Cubans’ travel, but that policies like the parole program for health professionals lend some restrictions legitimacy.

Rolando Anillo, an immigration lawyer based in Coral Gables, Fla., said that he had noticed cases in which the government had recently been more flexible in allowing doctors to leave, and that he believed that the new rules might let health care workers travel once they had completed a certain number of years of service. If such a policy shift were made, Niurka said, her two decades of service on a salary of about $25 a month should more than suffice.

“Working five days a week, long days, including a 24-hour shift?” she said. “I think I paid off my education in five years.”

She and her daughter would qualify for a United States visa under a program to reunite families, she said, complaining of the stress of waiting to see what her fate would be.

“I can’t go anywhere. That hurts,” she said, staring through her living room window at a torrent of rain outside. “But life goes on. You have to live in the moment, otherwise you become so bitter you can’t live at all.”