Saudi Arabia has released jailed activist Loujain al-Hathloul, best known for leading the campaign to legalize driving for women in Saudi Arabia, according to her family. She was held for nearly three years.

The 31-year-old activist was detained in May of 2018, along with several other female activists, just weeks before the Saudi government lifted the ban.

In December, a judge sentenced al-Hathloul to five years and eight months in prison, under a broad counterterrorism law. The charges against her include sharing information with foreign diplomats and journalists, and trying to change the Saudi system.

The judge suspended a portion of her sentence, and granted time served for another part, leading to her release on Wednesday. Al-Hathloul has already appealed her conviction under the counterterrorism law.

The move to release al-Hathloul is also seen as a gesture by the Saudi government to appease President Biden, who has called for a "reassessment" of the U.S.–Saudi relationship due to the kingdom's human rights record. Several other prisoners have also been released in recent days.

But al-Hathloul's case has been especially prominent. Around the time of her arrest in 2018, Saudi Arabia's Crown Prince Mohammed bin Salman was trying to establish himself as a social reformer and modernizer, opening up the kingdom to social changes. At the same time, he made it clear there was no room for any other vision of reform. He has cracked down on dissent, jailing clerics, businesspeople and activists.

While she was behind bars, al-Hathloul became an emblem of the struggle for women's rights in Saudi Arabia.

Her release this month was anticipated, and likely comes with restrictions on movement, talking to media, other activism and leaving the country, her family has said.

"For her, this is not freedom," her sister Lina told NPR from Brussels in the days before her release.

"The worst thing that could happen to her is to be forgotten once she's out and that people would just think that she's free and not talk about the case anymore," Lina al-Hathloul said. "And I think also she knows that she's a symbol now and that if she gives up, then she gives up on everyone else as well."

Abdullah Alaoudh, the research director for Saudi Arabia and the United Arab Emirates at Democracy for the Arab World Now, told NPR that al-Hathloul in particular has presented a problem for the kingdom.

"Her existence shattered the whole government narrative of empowering women. That's why it's a thorn to their side," he said prior to her release. "And the story of her comes up every time in the Saudi public and the Saudi imagination as somebody who challenges the Saudi system."

Al-Hathloul emerged as a prominent activist after graduating from the University of British Columbia in Vancouver and moving back to Saudi Arabia in 2013, her sister said.

She had been publicly expressing her opinion in Canada that the Saudi driving ban should be lifted, and decided to move back to the kingdom to continue the fight from there. According to her sister, she landed at the airport in Riyadh and drove home with their father filming her from the passenger's seat.

That was the first video that went viral, rocketing her to fame in Saudi Arabia, and it was just the beginning of a series of defiant moves that would bring her head to head against the powerful Saudi government.

Her impact has since grown beyond the kingdom, according to Simon Henderson, the director for the Bernstein Program on Gulf and Energy Policy at The Washington Institute.

Henderson said before her release that she "has become a symbol for a wide range of people, ordinary people, particularly in the West, perhaps in the Middle East as well, and that isn't going to alter."

As Saudi Arabia continues to face international pressure to improve conditions for women in the country, releasing al-Hathloul won't ease that pressure, Henderson said. He emphasized that because her release is conditional, with a 5-year travel ban and other restrictions, she will likely remain under close government watch.

"I'm sure that she will make a noise about it," he said. "And so the problem will escalate."

On al-Hathloul's case itself, her family expects her to keep fighting to prove that she and other prisoners were subjected to torture while detained – which a court in Saudi Arabia said earlier this week that she has failed to prove. She'll also push for the release of other activists.

Saudi Arabia's embassy in the U.S. did not respond to NPR's repeated requests for comment on al-Hathloul's case.