"(Border Force officials) have told the family they need to learn to adjust to what they're got on Christmas Island because they're not going to be brought back to the mainland," Tamil Refugee Council spokesman Aran Mylvaganam told AAP after speaking to the family.
"Priya, she is saying that she came from the war zone and regardless of how difficult it is, she's able to put up with it.
"But it's the children that she's worried about, who were born here."
Kopika was constantly asking when the family would be able to leave Christmas Island, where they were moved last month.
"She isn't coping well," Mr Mylvaganam said.
Supporters want the family returned to their adopted Queensland home town of Biloela.
Home Affairs Minister Peter Dutton's office has confirmed the family won't be returning to mainland Australia while their case is being determined.
It's expected to be months before a trial decides whether Tharunicaa's bid for a protection visa should be accepted by the Australian government. Her parents and sibling have already been denied refugee status.
Even if the court finds in favour of the visa application being permitted, the visa approval will be at the discretion of Mr Dutton.
Priya says her family is being put through "mental torture," according to Mr Mylvaganam, who adds their every interaction is being filmed by security guards.