Survivors of the atrocity on the Norwegian island of Utøya in July 2011 will never need reminding of the shootings that killed 69 young people. The detail of their frightening ordeal will stay sharp and stark.

But for Lara Rashid, a survivor who lost her elder sister, Bano, that summer’s day, the arrival of two major films telling the actions of the killer, Anders Behring Breivik, is a difficult test.

This weekend, after watching both Paul Greengrass’s new feature, 22 July, and Norwegian director Erik Poppe’s U – July 22, Rashid told the Observer she wished the films had focused on different parts of the story. But she welcomed their attempt to highlight the distorted rightwing ideology that lay behind the murders. “They miss out important perspectives,” she said.

Rashid was 16 when her sister was murdered. While she describes herself as supportive of the films’ motives, she is critical of elements.

Greengrass’s film, which was well received at the Venice film festival this month, uses real names, and gives much time to the killer’s story, charting Breivik’s path to the island after he set off a car bomb in nearby Oslo that killed a further eight people. Rashid, who helped the British director’s team, is portrayed in some scenes.

“Greengrass removes parts of the story. He has four white men as his main characters,” Rashid said. “Maybe he just finds that easier to relate to, but he should be making more of an effort to represent other sides.”

It was sad, she argues, not to see a portrayal of more of the powerful women who spoke at Breivik’s trial and held him to account. “A young friend of mine, 11 at the time of the killings, said she didn’t know about his hatred of women, so I feel there should have been more showing that.”

In contrast, Poppe’s film, which won standing ovations at the Berlin film festival and opens in Britain next month, takes the victims’ viewpoint and does not depict Breivik. The 72 minutes of its screen time reflect the real length of the outrage. It was shot in five consecutive days of one-take filming sessions and its central character is a fictional amalgam based on real testimony.

“To me, the Poppe film seems close to reality, because it showed a lot of what I experienced. It doesn’t reflect what happened to everyone, of course,” Rashid said. “It does bring it back, but it is worth it if it has an impact on the way people think.”

Rashid said she took the decision to see both films because they were being widely discussed in Norway and she “did not want to be the only one who did not have anything to say”.

Poppe’s decision not to portray specific individuals was right, she believes. “There is nothing the lead character does that didn’t happen to someone. He claims his is not a political film, although I am glad he does say what Breivik was. We have to talk about causes. It was a political act.”

Speaking this weekend, Poppe said he hoped to shift attention back to the survivors and victims and away from Breivik and Norwegian police failures. When he approached the survivors and the families of victims about the project, they were positive, he said. “They warned me there would be outspoken people who would say it was too early to make this. But they said I should not lose focus,” Poppe said. Their only true concern, he added, was that he might focus on just one person’s story.

After filming began, Poppe learned that the British Bourne-franchise director Greengrass was also making a film about Utøya.

“I heard it was based on the book One Of Us by Åsne Seierstad, so assumed it would have more to do with Breivik. I hoped our two films might work well beside each other,” said Poppe.

In 2006 Greengrass made the film United 93 about the plane brought down during the attacks on America on 11 September. He was criticised then for tackling the story on screen only five years after the event.

Poppe defends the right of a director to tell sensitive stories. “What is the purpose of art if we can’t go in and raise complex issues?” he asked.

Rashid, who works at the Norwegian embassy in Sarajevo, agrees the memory of the terrible events should be kept alive. “We have to stop people forgetting. It’s getting harder to hear that radical Muslims are not the only terrorists. There’s also a danger from rightwing extremism.”