WASHINGTON — Reality L. Winner, a former National Security Agency contractor who was the first person prosecuted during the Trump administration on charges of leaking classified information, has been released to a halfway house, her lawyer announced on Monday.

Ms. Winner’s case was the subject of an intense public campaign to win her a pardon or clemency. But it was her good behavior in prison, not the outside advocacy or a compassionate release process, that shortened her 63-month sentence, her lawyer said.

While her good-behavior release was not unusual, her lawyer, Alison Grinter Allen, said she and Ms. Winner’s family were worried that the government would find a reason to extend her prison stay.

“When we knew release was imminent, there were a lot of anxieties that it would be denied to her,” Ms. Allen said in an interview.

Ms. Winner was released on June 2 from Federal Medical Center, Carswell, a prison in Fort Worth, Texas, said Emery Nelson, a Bureau of Prisons spokesman.

The San Antonio Residential Re-entry Management Office will oversee her “community confinement,” Mr. Nelson added.

Ms. Winner is in a halfway house, where she will have access to the outdoors and be able to meet with her family, and then will be under supervised release, Ms. Allen said. She could be transferred to home confinement before her full release from custody in November.

While in prison, Ms. Winner was held under difficult conditions. The prison lost power and heat during last winter’s ice storms in Texas, and a number of fellow inmates died of Covid-19.

Her communications were closely monitored, and the government refused until now to move her to a less secure facility, Ms. Allen said.

“It was a terrible, terrible time,” Ms. Allen said. “Not that there is any great time to be in prison.”

A former Air Force linguist, Ms. Winner entered a guilty plea in 2018, after being prosecuted for leaking classified information. She had been arrested in 2017 and charged with sending a classified report about election interference to reporters at The Intercept.

The report described hacks by Russian intelligence operatives against local election officials and a company that sold software related to voter registration.

As Ms. Winner began to petition for a pardon or a commutation, Ms. Allen was added to her legal team because her other lawyers were banned from speaking publicly about the case.

Ms. Winner, now 29, sought clemency from President Donald J. Trump, with her legal team submitting thousands of letters in an effort to get him to intervene in her case.

There had been some cause to think Mr. Trump could commute Ms. Winner’s sentence. In 2018, he called her sentence “so unfair” and said that what she had done was “small potatoes.” But Mr. Trump never acted on the commutation request.

Despite Mr. Trump’s apparent ambivalence, the case was an early example of a campaign against leaks by his Justice Department.

While many of the Trump-era leak investigations moved slowly, the Justice Department announced the charges against Ms. Winner an hour after The Intercept published the article.

The Intercept came under criticism for how it reported the article, including by Ms. Winner’s mother. Ms. Winner had mailed the document to the publication anonymously, but the reporters showed a copy of it to the National Security Agency’s public affairs office and published the document to the internet, including markings that helped officials identify Ms. Winner.

In 2017, The Intercept acknowledged its practices fell short and said it should have taken more steps to ensure the identity of the person leaking the document was protected.

Ms. Winner could move relatively quickly from the halfway house to home confinement, where she could live with her family. Because of the pandemic, visitation had been cut off from the federal prison for the last 18 months and Ms. Winner had spoken to her family only on phone calls and occasional video calls. During her time in prison, Ms. Winner became an aunt and is looking forward to meeting her new family members, Ms. Allen said.

Once Ms. Winner is released from the halfway house, she will still not be able to talk about any of the documents she reviewed while working at the National Security Agency, but she will be able to speak broadly about issues that concern her.

“It would surprise me if advocacy and activism was not a part of her life going forward,” Ms. Allen said, “whether it be about the conditions and the state of mass incarceration or political prosecutions or election integrity.”