The orphan of an Australian Islamic State terrorist has described her harrowing journey from the clutches of IS to a Syrian refugee camp, where she is currently stranded with her heavily pregnant and injured sister and little brother.

Key points: Hoda, 16, Zaynab, 17 and Humzeh, 8, are in a refugee camp in Syria with Zaynab's toddlers Aiysha, 3, and Fatima, 2

Hoda, 16, Zaynab, 17 and Humzeh, 8, are in a refugee camp in Syria with Zaynab's toddlers Aiysha, 3, and Fatima, 2 Their grandmother said Zaynab is eight months pregnant, has shrapnel in her chest and is bleeding heavily

Their grandmother said Zaynab is eight months pregnant, has shrapnel in her chest and is bleeding heavily PM Scott Morrison says Australia is working to secure the children's release but will not risk Australian lives

Hoda Sharrouf, 16, is the youngest daughter of Australians Khaled Sharrouf and of Tara Nettleton, who took their five children to Syria in 2014 to join her terrorist husband. Both parents have since died.

Hoda, who is an Australian citizen, was only 11 at the time.

Now a teenager, Hoda and her brother Humzeh, sister Zaynab and her children were caught up in the final battle for Islamic State's last stronghold — the town of Baghouz in eastern Syria — which fell to Kurdish forces last month.

Hoda said Kurdish forces surrounding Baghouz were shooting at everyone during the offensive to re-take the town.

"They used to sit up there with sniper guns and stuff and they'd shoot everyone they'd see, even women and children," Hoda told the ABC's Four Corners.

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"They did a ceasefire they told women to leave, and I said I'm leaving I don't want to stay here anymore, so I left.

"I left, it was hard but I made it."

Hoda is in the al-Hawl camp where other IS families enforce hardline Islamic beliefs. ( ABC News: David Maguire )

Hoda has suspected nerve damage from wounds on her foot and ankle, which made the trip out of the town gruelling.

"It was just really hard, we had to walk up the mountain and it's steep," she said.

"Me with my foot, you know it's injured, you know the nerve doesn't work.

"I had to get, like, two people to help me as I kept falling on the ground.

"I was holding one small backpack on my back as well and I was about to chuck that but I had nothing."

Hoda and her siblings fled the regime and were taken to the al-Hawl refugee camp in the country's north-east, where thousands of wives and children of former IS fighters languish.

Conditions in the camp are squalid, disease is rife and medical care is poor and hard to access.

Hoda is desperate to escape the camp, where she does not feel safe.

"Once I leave here I never want to come back here ever again," Hoda said.

She hopes to return to Australia with her grandmother and siblings.

"I hope I can just spend as much time with my family as I can," she said.

Pregnant girl gravely ill: grandmother

There are fears for Hoda's sister Zaynab, who was married off when she was 13 years old to their father's friend Mohammed Elomar.

Khaled Sharrouf's daughter Zaynab (left) and her sister Hoda have been injured by shrapnel. ( Supplied. )

The eldest of the three surviving Sharrouf children, Zaynab —now 17 — is eight months pregnant with her third child.

Her Sydney-based grandmother, Karen Nettleton, has flown to Syria in a desperate attempt to secure the release of Zaynab, Hoda, and their brother Humzeh, 8, and Zaynab's two toddlers, Aiysha, 3, and Fatima, 2.

Ms Nettleton told the ABC that Zaynab is severely malnourished, has shrapnel in her chest and in the past 24 hours has been bleeding heavily and is unable to stand.

She was treated by a medical team at the camp on Thursday night, but there are concerns that Zaynab's life will be at risk if she remains there.

Khaled Sharrouf's children Zaynab (pink scarf), Hoda (black scarf), Abdullah (centre, deceased) and Humzeh (front). ( Supplied )

"She's malnourished, she's having stomach pains; she has constant diarrhoea," Ms Nettleton told Four Corners.

"I am so worried about that child, she really needs to be in hospital to be really checked out, she's like a skeleton."

The Australian Government is aware of the surviving children's plight, but says they are unable to help until the orphans leave Syria.

More than 100 children have died on the way to the camps or since arriving, mainly because of severe malnourishment, pneumonia and dehydration, according to humanitarian group the International Rescue Committee.

Zaynab's case has parallels with that of British teenager Shamima Begum, whose three-week-old baby died at one of the camps in March.

The British Government had refused to assist Ms Begum or her child and there was a public outcry in the UK after the death.

Grandmother's desperate flight to Syria to free kids

Karen Nettleton is in Syria trying to extract her grandkids from the Al-Hawl refugee camp. ( ABC News: David Maguire )

Ms Nettleton, Tara's mother, has spent five years trying to rescue her grandchildren from the toxic ideology of IS, after her daughter took the children to Turkey and then into Syria.

"They didn't know they were coming here, they all thought they were going to Turkey," Ms Nettleton told Four Corners.

"They crossed the border into Syria and it wasn't until some time later that Tara said to them they were in Syria.

Map Baghouz, where IS made its last stand in Syria, and the al-Hawl refugee camp to the north.

"They're just kids — they're Australian children, they're orphan children, they're my children — and they're not going to be a risk to anyone."

She rejected suggestions the children wanted to stay in IS-controlled territory for the past five years.

"It was impossible for them to get out," she said.

"Once you're in there you can't get out, you just can't; if you leave they would've killed you, ISIS would've killed you and you couldn't really trust people to take you out because they will turn you in to ISIS and you'd be killed."

Khaled Sharrouf was killed along with his two eldest sons in an airstrike in 2017. ( ABC News )

Ms Nettleton's trip to Syria is the third time she has flown to the region to retrieve her grandchildren: she travelled to Turkey in 2016 and 2018 but returned home empty-handed both times.

This attempt may have more success, as other foreign children held at the Syrian camps have been rescued by their home countries.

In March the French Government reportedly repatriated a group of five orphaned IS children from the al-Hawl camp.

About nine other countries including Egypt, Indonesia and Russia, have also been able to repatriate hundreds of their children.

"I want the (Australian) Government to assist in getting the children home," Ms Nettleton said.

Australia 'working with aid agencies'

Baghouz fell to US-backed Syrian Democratic Forces (SDF) troops last month. ( Reuters: Rodi Said )

Prime Minister Scott Morrison has maintained he will not risk Australian lives extracting people from conflict zones, but on Friday indicated the Government was open to working with aid agencies to facilitate their passage.

"Where there are children, and mainly that's where our focus is, I'd say exclusively that's where our focus is," Mr Morrison said.

"Then we are working with the Red Cross so that where they're in a position for people to get to a place where they might be in a position to return to Australia then we will cooperate with that process."

Mr Morrison said provided the children passed "normal assessments", the Government was open to assisting their return to Australia.

"There are issues relating to people's citizenship that has to be confirmed, and you'd expect that," he said.

"But where those issues are able to be addressed, we would follow the normal processes for issuing of travel documents after all those other matters have been addressed.

"But I am not going to put one Australian life at risk for that.

"In the case of [Australian] children, who are the innocent victims of those who took them into this atrocious place … we will do what I think Australians would expect us to do on their behalf."

The family's lawyer, Robert Van Aalst, said the comment was heartening.

"It's been a long time coming, and I'm glad that Scott Morrison has moved his position from not wanting to deal with it at all, to, he puts children in a different position, and to actually come out and say he's going to assist the children," Mr Van Aalst said.

He said the first step would be getting the children out of the camp, and getting Zaynab urgent medical attention.