When Indonesian schoolgirl Nur Dhania arrived in Syria in 2015, she knew almost immediately that convincing her family to join her in the 'caliphate' was a catastrophic error.

Key points: About 800 Indonesians have travelled to Iraq and Syria to join IS since 2014

About 800 Indonesians have travelled to Iraq and Syria to join IS since 2014 Nur Dhania convinced family members to go to Raqqa to live with her in the 'caliphate'

Nur Dhania convinced family members to go to Raqqa to live with her in the 'caliphate' Her father and uncles are in prison for terrorism-related offences

Just 16 years old at the time, Nur Dhania said life under Islamic State rule was nothing like the paradise portrayed in the group's propaganda.

She felt duped — and totally responsible for her family's predicament.

"I was a spoiled brat. I refused to listen to other people. I was arrogant, stubborn," she said.

Nur Dhania was the first member of her family to decide to leave Indonesia for the caliphate, a huge swathe of territory stretching from western Syria to eastern Iraq, controlled by the Islamic State.

Incredibly, 25 of her relatives — including her grandmother, sisters, parents, uncles, aunts and cousins — followed her.

But within a year, the family was willing to risk everything to get home.

'I was mesmerised'

Nur Dhania first heard about the Islamic State group from her uncle, who is now in prison in Indonesia on terrorism offences and was also instrumental in persuading other members of the extended family to travel to Syria.

That year — 2014 — she spent her school holidays glued to social media, where she devoured everything she could find about Islamic State and its promise of a 'paradise' in Syria.

She claims she was never radicalised by Islamic State or motivated by jihad, but was instead seduced by the promise of a utopian life.

"I was mesmerised," she said, by Islamic State propaganda that offered free housing, education and healthcare; jobs for everyone who joined the cause, and a promise to pay the family's debts.

She tried to convince her family of the benefits of leaving Indonesia for Syria, and briefly ran away from home when they refused to join her.

Nur Dhania (right) with her father and sisters before they left for Syria. ( Facebook: Dwi Djoko Wiwoho )

Terrified for their daughter's safety, Nur Dhania's parents eventually made a stunning choice.

Her father Dwi Djoko Wiwoho abandoned his middle-class job as a respected senior civil servant on Batam Island in Indonesia's Riau Province.

He sold the family's main home in Jakarta to fund the voyage to Syria, via Turkey.

In the weeks and months that followed, 26 family members travelled to the Middle East. Seven were detained in Turkey and deported.

But 19 family members, including Nur Dhania and her parents, made it to Raqqa.

AK-47s, filthy dorms and relentless marriage proposals

As soon as the family arrived in Syria, they were segregated and forced to live apart.

Women and girls were housed in a filthy dormitory with other women they didn't know. Physical fights and domestic disputes were common, as was theft.

Islamic State fighters regularly came to the dormitory to pressure Nur Dhania, her sisters and other young women to marry. They repeatedly refused.

Nur Dhania's male relatives were taken to a weeks-long camp to learn about Sharia rule.

They were taught to use weapons, including AK-47s and rocket-propelled grenades. But Nur Dhania is adamant that her father and uncles refused to fight.

"All we wanted was to be civilians," she claimed.

Eventually the family was given a house by Islamic State's administrators.

But Nur Dhania said that when her male relatives refused to take up weapons to fight, the Islamist regime turned on them.

"They ordered and forced people to go to battle. But the Koran says that not everyone has to go to the war, and some people need to stay in town," she said.

They expected to find paradise in Raqqa. But within a year, the family was falling apart.

Her grandmother had died from an illness. One uncle had been killed in an airstrike. Another had disappeared altogether.

The 17 survivors decided it was time to make their escape.

Fleeing the caliphate

Nur Dhania kept the shoes she was wearing when they escaped Syria. ( ABC News: Ari Wu )

Nur Dhania said it was no easy task to find someone willing to smuggle them to the Kurdish border, without betraying them to Islamic State leaders.

One smuggler stole their belongings including money, mobile phones and laptops.

A second smuggler also duped them.

Finally, a third smuggler drove them to the Kurdistan border, where they narrowly avoided being shot by snipers as they approached a checkpoint.

The family spent two months living in tents in a UN refugee camp guarded by Kurdish forces.

Nur Dhania met a journalist at the camp and told them it was her fault that she and her family had ended up there.

Sorry, this video has expired Nur Dhania spoke to AP at a refugee camp run by Kurdish forces after she escaped ISIS in 2017

Eventually, Indonesian authorities agreed to facilitate the family's return.

Two years after they left, the family flew home to Jakarta — but their ordeal was not over.

Indonesian police and anti-terror agents were waiting to detain them as they stepped off the plane.

The entire family was taken into custody by Indonesia's anti-terror agency BNPT.

Facing the consequences

The issue of returning Islamic State fighters is a vexing one for Indonesian authorities.

An estimated 800 Indonesians are thought to have travelled to Iraq and Syria since Islamic State declared the caliphate in 2014.

About half — including Nur Dhania and her family — have since returned.

Until last year, it was not illegal under Indonesian law to join a militant group overseas.

But Nur Dhania's father and two uncles were still charged with terror-related offences because they underwent paramilitary training in Raqqa.

Nur Dhania's father was sentenced to nearly four years in prison on terrorism offences. ( ABC News: Ari Wu )

Last May, Dwi Djoko Wiwoho was sentenced to three years and six months in jail. The uncles received similar jail terms.

"Police said all of us should have been convicted, but because of their conscience, only the adult men were charged," Nur Dhania said.

"They accepted that we're no longer dangerous, but they had to follow legal procedures," she said.

The rest of the family spent several weeks in a 'deradicalisation' program before they were released.

The former head of Indonesia's anti-terror agency BNPT, Ansyad Mbay said in 2017 that it was important they be given a second chance.

"Yes, they have shown allegiance to IS, but they have been deceived. From a humanity point of view, who else would accept them if we don't? We can't just throw them into the sea — especially after they have shown their remorse," he said.

"We all can take a lesson together out of this. Let's embrace them back into society and learn from their mistakes."

Nur Dhania and her family visit her father in jail about once a month.

She said he still shows anger towards her.

Ratna Nirmala sells simple handcrafts at a local market to support her daughters. ( ABC News: Ari Wu )

"Sometimes he's upset and angry. Not only my father, but also my mother is angry with me. My sister sometimes says that it's all because of me. I feel guilty of course," Nur Dhania said.

'It's all our fault collectively'

Now 20, Nur Dania believes she will spend the rest of her life blaming herself for the tragedy that befell her family.

After losing her father's former income and most of the family's wealth, she is struggling to return to a normal life with her mother and sisters.

They live in a relatively poor community south of Jakarta where they've sought to conceal their past from their neighbours.

Nur Dhania's mother, Ratna Nirmala, and her daughters sell simple handcrafts at a local market to earn a meagre income to support her daughters.

She struggles to pay for the girls' upkeep and education, but she accepts some of the blame for the family's tragedy.

"It was my fault too," says Nur Dhania's mum, Ratna Nirmala. ( ABC News: Ari Wu )

"I don't just blame [Nur Dhania] because it was my fault too. It's all our fault collectively," Ratna Nirmala said.

"We can't continue to blame one another for what happened or it would never end. Everyone makes mistakes."

Asked what she now thinks of Islamist extremism, Nur Dhania described IS as "extremely cruel."

"They says it is Islam, that their jihad is war. But they should read the Koran again. Jihad isn't war."

"They wage war and spill blood and they think it's right, but that's not what God teaches us. Islam means peace," Nur Dhania said.

She is well aware that many Indonesians don't believe her claims that her father and uncles had no wish to fight.

"They don't know me. [They should] get to know us, see who we really are ... listen to our stories. That's all I can say to them," she said.

Nur Dhania hopes to become an author and take an active role to discourage others from making the mistakes she did.

"Hopefully I can get the message across so no one will experience what my family and I went through, and they're more careful with what they see on the internet.

"This is my way of spreading peace and truth to people around the world," she said.