“I constantly take sleeping tablets because being awake is too hard,” says Narges. “I understand that as a 27-year-old woman, the Australian Border Force considers me an independent. However, this is not the case in our culture and therefore life without my mother is meaningless for me.”

Narges and her brother, Daryoush, currently languishing on Nauru, have not seen their mother and sister since 2014, despite multiple officials strongly and repeatedly recommending they be reunited.

The family of four are Hazara refugees from Afghanistan. They arrived in Australia in 2013 after travelling through Pakistan and Indonesia, and were sent to the offshore processing centre in Nauru. All have refugee status from the Nauruan government.

But in August 2014 their mother was transferred to Darwin for urgent medical care, and only one of the three siblings was allowed to join her two weeks later.

The family has been separated ever since. The mother and sister cannot apply for US settlement unless they return to Nauru, but the mother’s health won’t allow her to.

Narges and her brother have both suffered mentally and physically after the separation. Narges has self-harmed and attempted suicide. Both have been diagnosed with illnesses including severe depression and post-traumatic stress disorder.

Narges has had an ear infection for two years, which she says has not been properly treated and is now affecting her hearing. Daryoush was supposed to go to Papua New Guinea for medical treatment but refused to leave his sister.

Narges and her brother Daryoush live in the mouldy tent accommodation inside what used to be the Nauru detention centre.

Both have been repeatedly recommended for family reunification by the numerous service providers that are paid by the Australian government to take care of them.

Guardian Australia has seen multiple reports from the health contractor, International Health and Medical Services (IHMS), which include regular and repeated recommendations for the urgent reunification of the family on the basis of severe mental health issues.

“Narges continues to experience significant situational stress because of her separation from her mother,” said a 2014 report.

“She is continually being reviewed by the mental health team and is provided guidance on how to try to cope and manage the great deal of stress. The psychiatrist’s recommendation for Narges is to be transferred to Australia and reunited with her family, as a matter of priority.”

A 2015 report said: “IHMS psychiatrist recommends for the family to be reunified, as the family needs to be together for the sake of the mental health of the brother and sister.”

And in 2016: “The IHMS psychiatrist involved in her care has provided several reports stating Ms Narges remain at risk of further deterioration, which was proven by an incident of Ms Narges’ attempt to self-harm by means of overdosing.”

Guardian Australia understands further reports in 2017 and 2018 continue to outline the diminishing health of the siblings and recommend they join their family in Australia.

Narges is believed to be the only Hazara woman on Nauru. She and her brother live in the notoriously mouldy, hot and ill-equipped tent accommodation inside what used to be called a detention centre.

How can a sick person get better when suffering from separation of family? Narges

“Where I am living is not adequate and healthy, even for animals,” she says. “If I was in Kabul, I might be killed once, but on Nauru, I am dying a slow death every day. Separation from my country – Afghanistan – is much easier than separation from my mother. I sincerely believe that reuniting with my mother can save my life, and humbly ask for consideration of my critical state.”

Narges and Daryoush have written to the various service providers contracted throughout their detention more than a dozen times. These include Transfield Services, Canstruct, Save the Children and Australian Border Force (ABF).

“My mother needs our help, our support because she is sitting on the wheelchair,” wrote Narges in March.

“She has a lot of pain; also she is emotionally under pressure. I ask to you what kind of treatment is this? How can a sick person get better when suffering from separation of family?”

At least six replies that have been seen by Guardian Australia acknowledge receipt of their letters but provide no solution.

One, from ABF in January of this year, bluntly told Daryoush to stop contacting them until he can come up with “substantive new issues”.

Narges says ABF has told her that reunification is in fact possible – if her mother returns to Nauru.

That has been determined by doctors as highly unlikely, given Nasreen’s condition. She is confined to a wheelchair with spinal conditions that have left her “profoundly disabled”, and is awaiting surgery.

At least part of her condition stems from injuries sustained when she was severely beaten in Afghanistan while trying to shield her son.

There are numerous cases of family separations enforced by the Australian government which, when it can be convinced to transfer someone for medical care to Australia, will almost never allow family to come with them.

“The government is well aware that this practice harms people, especially vulnerable women and children, but they persist with it in the face of all the evidence,” the human rights lawyer, George Newhouse, says.

The Australian government also shows a consistent refusal to act on advice from its service providers. In 2016 it was revealed a young woman, a rape victim, was left on Nauru for months despite recommendations from every authority on the island – including its government.

“I’ve seen case after case where government officials simply turn a blind eye to expert advice that indicates that family members are at risk of real harm and even death because of government inaction, and yet they ignore that advice,” says Newhouse.

Newhouse says the government must “urgently” fill the still vacant role of chief medical officer at ABF, held for two years by Dr John Brayley until September.

“At least when they have a medical practitioner in that role there was someone advocating for the health and welfare of asylum seekers on the inside.”

In Sydney on Saturday, more than 400 doctors and medical students rallied against detention, and against the lack of response from government to their concerns.

The protest was organised by the peak body for medical students, Australian Medical Students’ Association, which called for an end to “unacceptable and inhumane” offshore processing, and for independent health assessments of refugees and asylum seekers.

IHMS were contacted for this story but all questions were referred to the Department of Home Affairs, which said it does not comment on individual cases. The office of the minister, Peter Dutton, did not respond to questions.