The family of a young mum tortured and murdered in Queensland say she’s done bad things in the past, and are desperate for answers about her death.

The sister of a young Queensland mother tortured, murdered and left to rot in a bushland grave is desperate for answers.

Police allege 28-year-old Tia Landers suffered a violent end at the hands of a de facto couple who tortured her at their home north of Brisbane before killing her and leaving her body in a shallow grave in a state forest.

Officers had been looking for the mother-of-four, whose youngest child is just three, for almost three weeks before making the grisly find at Beerburrum on Thursday.

A couple known to Ms Landers has been charged with torturing and murdering her and will spend at least the next six months behind bars after they were remanded in custody during a court mention on Friday.

John Edward Harris, 42, and Linda Eileen Appleton, 40, did not appear in the Redcliffe Magistrates Court, where the matter was adjourned until January 12.

Police say Ms Landers went willingly to the couple’s home at Brighton, north of Brisbane.

Officers who’ve combed the property say there are signs she was brutally tortured there, but they have not revealed the nature of her injuries or the cause of her death.

“There’s evidence that there has been violence at Newport Street,” Detective Acting Superintendent Damien Hansen told reporters.

“The offenders have been charged with torture.”

Jamie Landers, 19, was at the court on Friday and said her family was desperate for answers.

“We want to know why. Tia’s done a lot of bad stuff in her life, we all know that (but) it’s not to be held against her,” she told reporters outside the court.

“She is a mother of four children, her youngest daughter is three years old, her oldest son is 10. They are struggling.”

A friend of the slain woman has told ABC radio she was a loving mother.

“I’ve known her for eight years, she was there for me always, ups, downs,” Angela Dicker said. “Loving mother, loving daughter, loves her parents, loves her family.”

A post-mortem examination is being carried out as the police investigation continues at the forest site where the body was found, and the Brighton home.

Supt Hansen said Ms Landers was no stranger to the couple charged with her murder.

“She’s an associate of theirs. They’re known to each other, have been known to each other for some time,” he said.

He said police had put Ms Landers in the high risk category after she went missing.

She was last seen alive on June 16 in the Deception Bay and Redcliffe areas and her family reported her missing a few days later.