A girl suffering “resignation syndrome” and who is refusing all food and water has been ordered off Nauru by an Australian court, as a succession of critically ill children are brought from the island.

At least three children have left the island since Thursday, and reports from island sources say at least three more children, as young as 12, are “on FFR” – food and fluid refusal.

The current crisis on the island is overwhelming medical staff, who are referring dozens of children for transfer off the island, only to have their decisions rebuffed by Australian Border Force officials on the island or department of home affairs bureaucrats in Canberra.

Two children were moved off the island with their families on Thursday.

Early on Friday morning, a 14-year-old refugee boy suffering a major depressive disorder and severe muscle wastage after not getting out of bed for four months, was flown directly from Nauru to Brisbane with his family. There are concerns, doctors say, he may never be able to walk normally again.

Later on Friday, in the federal court, Justice Tom Thawley ordered another girl – given the designation EIV18 by the court – to be moved to Australia for urgent medical treatment.

Court orders prevent publication of the girl’s age – other than the fact she is a child – her name or country of origin.

Guardian Australia reported on the girl’s case on Wednesday. Three separate doctors had independently assessed her, and all had recommended she be moved urgently from the island, but this was resisted by the Australian government.

The girl has been inside the supported accommodation area of the regional processing centre for three weeks, and has been refusing food and water for much of that time.

Before she, too, fell into acute depression and “resignation syndrome”, and refused to eat or drink anything, she had been one of the brightest and most articulate of the refugee children on Nauru.

“Before she got sick, she was the best-performing student,” a source familiar with the girl and her condition told the Guardian. “She had a dream to be a doctor in Australia and to help others. Now, she is on food-and-fluid refusal and begging to die as death is better than Nauru.”

The girl told her Australian advocate: “I can’t live in this island anymore. I hate everything and everyone around me. I hate to go outside.

“We left our country to have a good and better life, but we faced the worst life ever, the life which forced us to end it.”

What kind of a world do we live in where life-or-death medical decisions need to be decided by a judge? NJP principal solicitor George Newhouse

The court ordered the girl be moved “on an urgent basis” from Nauru. The next commercial flight is not until Sunday, but doctors have said the girl is too unwell to take a commercial flight.

A department of home affairs source in Canberra confirmed to Guardian Australia an air ambulance flight had been approved for the girl, but the government was waiting on arrangements to be made for her family.

Guardian Australia has been told by sources on Nauru that up to three more refugee and asylum seeker children are on food and fluid refusal on the island, including two brothers aged 14 and 15.

Only the most critically ill cases are being addressed, Nauru sources say, and the situation is “dangerously chaotic”. A 12-year-old girl who attempted to self-immolate this week has not been moved.

In the case of a 12-year-old boy who’d eaten no food for 20 days, he was reportedly just hours from death when he was moved by air ambulance on Tuesday. He weighed just 36 kilograms and could not stand up when he was taken to the airport.

Island sources say there is an uncontrollable “contagion” of children committing self-harm, attempting suicide or refusing all food and fluid.

Several children have been diagnosed with the rare but serious child psychiatric disorder “pervasive refusal syndrome”, also known as resignation syndrome, which has been documented at high rates among asylum seeker children, especially in Sweden.

Children suffering resignation syndrome effectively withdraw from life – refusing to eat, drink, go to the toilet, leave their beds, speak or even open their eyes. They are sometimes completely unresponsive to stimuli.

The National Justice Project, which has succeeded in having more than a dozen children transferred off Nauru through court applications – either conceded by the government or ordered by judges - said there was a child health crisis on Nauru.

“The National Justice Project is overwhelmed with cases of desperately sick children on Nauru,” the NJP principal solicitor, George Newhouse, told Guardian Australia.

“What kind of a world do we live in where life-or-death medical decisions need to be decided by a judge?

“I’m very concerned about the difference between the medical reports we are seeing and the information the government is using to base its decisions.”

The Australian government has consistently declined to comment on individual cases, but the Nauru government has defended the safety of children on the island.

“Children of refugees and asylum seekers on Nauru have access to education, health services, welfare, good accommodation and a range of social services provided by the Nauru and Australian governments. Nauruan children grow up happy and healthy on our island. Activists [are] playing politics and distorting facts,” the government said in a statement.

“Media reports about children of refugee and asylum seeker families in Nauru are false. None are in detention. They live with their families in our community alongside Nauruan children. To suggest any child is in danger just because they live in our country is offensive.”