Yekaterina Samutsevich, the Pussy Riot member freed by a Moscow court this week, has promised to continue taking part in the band's anti-Putin protests, saying she would be "more careful and more clever" to avoid another arrest.

On Friday, in her first newspaper interview, Samutsevich said her parting words to the two band members who remain in jail were that she would continue their struggle against the president. But she expects state pressure on her to grow despite her new-found freedom

"They didn't overturn the verdict, they didn't say I'm not guilty – they gave me a suspended sentence. If I do the slightest thing [wrong], even an administrative violation, they can send me back to jail," she told the Guardian.

The three women were sentenced to two years in a prison colony on charges of "hooliganism motivated by religious hatred" following their anti-Putin "punk prayer" in a Moscow cathedral. Samutsevich was unexpectedly freed by an appeals court on Wednesday after successfully arguing that she didn't fully take part in the performance.

"I didn't expect it," Samutsevich said, sitting in a central Moscow cafe wearing the same jeans and white sweater she wore to the appeal hearing. At her feet lay a canvas sack and large plastic bag filled with clothes, letters and books. She had just collected her belongings from the southern Moscow detention centre that still holds her bandmates, Maria Alyokhina and Nadezhda Tolokonnikova.

Samutsevich described how the three friends had prepared themselves for prison during the appeal hearing. "In court, we were talking about how we would go to the prison colony, what it would be like. When they took us back into the courtroom, we said: that was a very short deliberation, they probably won't change the verdict." (A panel of three judges deliberated for just 40 minutes before announcing Samutsevich's release.)

She struggled to explain the judges' thinking. "Maybe the authorities wanted to imitate the independence of the court system," she said. "But it is just that – an imitation."The case against Pussy Riot was one of most high-profile political trials in Russia since Putin first came to power 12 years ago. The president has condemned their performance and their name, while Dmitry Medvedev, the prime minister, said he was "nauseated" by the group's action.

Samutsevich said Putin stood behind the decision to prosecute the band. "Such decisions don't happen without the president," she said. "It was either motivated by personal hate or it was a political step." The appeal judges held a rare press conference on Thursday to press that they made the decision independently and with no pressure from above.

"They're trying to marginalise us, to say we're not normal people," she said. "We were jailed for our political beliefs."

Pussy Riot formed after Putin announced late last year that he planned to return to the presidency – a move that prompted mounting discontent to spill into the streets with a growing protest movement which vowed to prevent a return to totalitarianism.

The arrest of the three band members in early March was seen as a signal to other protesters. The Duma, Russia's parliament, has since adopted a series of restrictive laws imposing fines on illegal protests and broadening a law on treason. "Putin is a person who doesn't want to listen to the citizens of Russia," Samutsevich said. "People complain and he ignores it all. Instead his government adopts awful laws – that's his answer to citizens' attempts to talk to him," she said.

Samutsevich said she would continue taking part in Pussy Riot's anonymous performances. She does not worry that she is now recognised, often by people on the street.

"When a person is in a mask and a dress, she can become anonymous again," she said. As for the fear of getting caught, she said: "I will be more careful and more clever."

She thought Russia's security services would step up their surveillance. "I must live imagining that everything is listened to, everything is read."

Samutsevich said Alyokhina and Tolokonnikova were happy with her release. As they hugged goodbye inside the courtroom's glass cage, her fellow band members said: "Finally, one of us is free." Samutsevich recalled: "They said: keep going with the group and I said: of course."

Alyokhina, 24, and Tolokonnikova, 22, both mothers to young children, are expected to be sent to distant prison colonies to serve the rest of their sentence until March 2014.

"Masha [Alyokhina] especially is suffering for her child," Samutsevich said. "It's a big blow for her– for Nadya too. They have hardly seen their kids."

Samutsevich described her seven months in pre-trial detention as a time of cold isolation in which the system exercised "total control". Wake-up came at 6am and lights out at 9pm. In between, there were three meals a day – porridge for breakfast, soup or a potato for lunch, and porridge or soup for dinner.

Once a week, she was allowed 30 minutes of privacy for a shower. Otherwise, she was led everywhere by a guard.

She shared her cell with three women, all charged with economic crimes. They were subjected to random searches, as guards hunted for banned items such as mobile phones. "That's what they said, but they always read my letters." Samutsevich said she would get around a dozen letters a day from supporters.

Sometimes she read classics from the prison library, turning especially to Nikolai Chernyshevsky, the philosopher who wrote Russia's classic revolutionary novel, What is to be Done? Other times, she watched television in her cell.

At first, her cellmates treated her with suspicion. "They didn't understand who I was or what we did," she said. That changed as reports on the Pussy Riot case started to run on television. "Then they started to support me, and by the end they really took care of me," she said.

Samutsevich said she was sorry to leave Alyokhina and Tolokonnikova – but added that even in jail they were unable to spend time together: each one was held on a separate floor. "I miss them. But I missed them [in prison] too – we could never talk.

"We could only talk when we were driven to court and back during the trial," she said. "Those were the best times in the whole seven months. We had time to talk about different subjects – films, books, articles, and, of course the case, our thoughts about the day."

The three women were deprived of information from the outside world, but kept informed of events by their lawyers.

"One day in court, the lawyers showed us photos. We didn't understand what it was. Then they explained it was Madonna, with writing on her back supporting us," she said.

That was when she understood the whole world was watching. Madonna was one of a handful of artists who performed in Moscow, and who came out in support of the jailed band.

"All this solidarity meant we were understood in modern cultural society," Samutsevich said. "That was very important to us."

She has spent her two days of freedom shuttling between Russia's few independent media outlets, hoping to keep the spotlight on her two jailed friends.

Asked if she could repeat the church performance, she hesitated for just a moment. "Yes, I would probably do it. It was important for us to do it, to express our opinion.

"I saw the system from the inside," she said of her time in prison. "I saw how this punitive system doesn't work, how it doesn't acknowledge personal dignity."

Asked about performing with some of the western artists who have come out in support of the band, she declined. "Our group is made for unsanctioned concerts," Samutsevich said. "The symbol of the group is still a girl in a balaclava."