Supporters in the tiny Queensland town of Biloela are concerned for the health of a two-year-old Tamil asylum-seeker held in detention for 15 months.

Tharunicaa - the youngest daughter of failed asylum-seekers Priya and Nadesalingam - has severe tooth decay and needs surgery urgently, family friend Angela Fredericks says.

Four of Tharunicaa's teeth are so rotten nerves are exposed, Ms Fredericks told AAP on Sunday.

"Priya says she won't eat solids because her mouth hurts so much and two teeth are now dead," she said.

Ms Fredericks said a lack of sunlight and a poor diet since the family was taken into custody during a dawn raid on their central Queensland home are to blame for the decay.

"It's been tough getting access to specialists," she said.

Doctors want to operate to remove the teeth but no date has been set.

It came as Australian-born Tharunicaa celebrated her 2nd birthday in detention.

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Ms Fredericks said supporters took a cake to the detention centre but staff confiscated the candles.

Priya, her husband Nadesalingam, Tharunicaa and her sister, Kopika, 4, have received a temporary reprieve from deportation, however.

In late May, Immigration Minister David Coleman agreed not to deport them until Tharunicaa's asylum claim is heard.

The family had been at imminent risk of deportation after the High Court denied their final bid to stay in Australia on May 14.

Their case is complicated, however, because Home Affairs has placed a bar on Tharunmicaa making an asylum claim, Ms Fredericks said.

"It's ridiculous. There's a whole community here in central Queensland ready to support this family - we want them back here."

Priya, Nadesalingam, Tharunicaa and Kopika remain much-loved members of Biloela, where they lived before the Australian Border force took them into custody.

Nadesalingam worked in the local meatworks and Priya's curries became a sought after delicacy.

The couple came to Australia separately by boat in 2012 and 2013 following Sri Lanka's civil war and settled in town for four years on a temporary bridging visa, which ran out in March 2018.

Kopika is also born in Australia.