Home to Bilo campaign organiser Angela Fredericks said that for three-year-old Tharunicaa, life in detention is basically all she knows.

"She has literally only ever spent Christmas in detention, so it's very sad," she said.

Parents Priya and Nades and their girls Kopika and Tharunicaa have now passed more than 1000 days in detention.

The family was taken from their home in the central Queensland town of Biloela to an immigration facility in Melbourne in March 2018.

Kopika, aged 5, began prep this year.

"For her that real stark realisation of just how different her life is to her peers, that's brought a lot of very tricky questions," Ms Fredericks said.

She speaks to Priya on a weekly basis and said the toll of indefinite detention is affecting both parents' mental health.

"It's very hard for Priya to really trust people connected to immigration," she said.

"We just honestly have no idea when the end is in sight, however we know it could literally be over tomorrow if those men in power actually just made the right call."

A statement from the Department of Home Affairs says the family has access to health and welfare services and their detention placement is regularly reviewed.

"Australian Border Force (ABF) has deemed the current placement suitable for the family," it says.

The department said ABF regularly consult the family around any concerns to accommodation arrangements to ensure suitability and make changes where warranted.

"No concerns have been raised by the family in relation to these arrangements," it states.

Australian Associated Press