The woman charged with murdering her three-year-old daughter has died after being found unresponsive in her Brisbane jail cell.

Lauren Ingrid Flanigan, 32, was arrested in the front yard of her Bundaberg home last Monday, in Central Queensland, after her daughter Sophia Rose was found in a critical condition with “multiple wounds” on her body, according to Queensland Police.

The young girl died at the scene.

Know the news with the 7NEWS app: Download today

Flanigan was rushed to hospital from the Brisbane Women’s Correctional Centre on Friday night after being found unresponsive in her cell.

She died in hospital overnight.

Initially, it was suspected Flanigan may have overdosed.

If confirmed by autopsy, it would represent a serious security breach within one of Queensland’s highest-security facilities.

“Even someone who’s charged with murder should have the proper protection in custody,” said criminal defence lawyer Vered Turner, who represents clients at the Wacol jail.

Premier David Crisafulli also weighed in, saying: “It’s important that we don’t brush it under the carpet and this incident proves there are some explanations that are needed.”

Turner added resources inside the prison are “stretched absolutely to the max” and that “there are lots of prisoners not getting the help they need.”

Police said a report would be prepared for the coroner, and had earlier confirmed detectives from the Corrective Services Investigation Unit (CSIU) are investigating.

“Queensland Corrective Services (QCS) officers provided immediate assistance before paramedics transported the woman to hospital, where she died last night, June 1,” they said.

“Support is being offered to the responding officers and their colleagues,” corrective services said in a statement on Saturday.

Flanigan was being held in custody until her next court appearance in July after being charged with murder last Monday.

She had not yet entered a plea.

Sophia’s father, Jai Ruane, was not at home at the time of the incident. It’s understood the 39-year-old is a FIFO worker at a coal mine.

He has now returned home and is caring for his other two children.

Ruane opened up about his “bubbly” daughter Sophia, telling 9NEWS “she was the light of (my) life”.

“She was always smiling, always wanting to help, just so full of life and love. She just had such a huge heart,” Ruane said.

Flanigan’s death not only spares her from a life behind bars, it also leaves the most pressing question unanswered: why was Sophia’s life taken?

“I’m not confident at all that we will get all of the answers. I do believe we will get some answers, though,” said Bundaberg Mayor Helen Blackburn.

It’s expected the coroner will now examine both Sophia’s murder and the circumstances of Flanigan’s death.

-With AAP

If you need help in a crisis, call Lifeline on 13 11 14.

For further information about depression contact beyondblue on 1300224636 or talk to your GP, local health professional or someone you trust.