Devastating new details of Kate Goodchild's final moments before her death in her husband's arms.

The mother-in-law of Kate Goodchild has revealed the heartbreaking details of how her son held his wife in his arms at Dreamworld as she died as their 12-year-old daughter looked on.

Kate Goodchild was one of four adults who died on Tuesday at the fun park. She was in the Thunder River Rapids ride with her 12-year-old daughter, Ebony, her brother, Luke Dorsett and Luke’s partner Roozi Araghi.

Another woman, Cindy Low, also died in the tragedy. Her 10-year-old son and Mrs Goodchild’s 12-year-old daughter, Ebony survived with police describing their escape as a “miracle”.

Gillian Turner told of how Kate Goodchild’s husband, David Goodchild had waited by the ride’s exit with their eight-month-old daughter Evie in a pram for his wife and daughter to finish.

"My son managed to reach his partner ... who died in his arms while their 12-year-old daughter looked on screaming in the background." Image via Facebook.

A devastated Mrs Turner told media yesterday that her son heard the commotion and ran to save his high school sweetheart.

"My son managed to reach his partner ... who died in his arms while their 12-year-old daughter looked on screaming in the background," she told media.

"My son and Kate were childhood sweethearts and she will be missed incredibly."

In a statement to reporters in Canberra, Ms Turner says she'd like to believe her 12-year-old granddaughter was saved, so she could tell her little sister what a wonderful mum she had.

"Kate is irreplaceable, she is not only going to be missed by my son and grand-daughters but by a lot of people."

Ms Turner said the families involved were "devastated and inconsolable".

She tearfully relayed the little things that were breaking the hearts of those impacted, like Ebony, saved by the grace of god, now left without her mum.

“She used to braid her hair for her, and she doesn’t know who is going to braid her hair for her now."

Gillian Turner addressed media in Canberra.

Mrs Turner questioned how this tragedy, on what should have been a fun family day out could happen.

"When you think it's a ride that two-year-olds can go on, how can something like this happen?" she said.

"Kim [Kate Goodchild's Kim Dorsett] and Shayne have lost a son and a daughter in what can only be called a devastating and horrific disaster.”

"Until we get answers on how it happened and why it happened, I don't think any of us are going to rest."

Her comments were echoed last night on The Project in an email from Kate Goodchild’s surviving brother, Jeremy Dorsett.

He lost his brother and sister.

The victims. Cindy Low,  Kate Goodchild, Luke Dorsett and Roozi Araghi.

Host Carrie Bickmore read Mr Dorsett’s message where he said to lose both siblings on the same day was “indescribable”.

“The focus needs to be on children without mums, and kids who had to witness such an event. There were a lot of families that were there who were changed forever today,” he said.

“Mums and dads lost children, children lost parents, brothers lost sisters. Husbands lost wives. The world’s gone mad.”

But Mr Dorsett he appealed for calm.

“Please refrain from pointing any fingers,” he wrote. “Authorities have a lot of work to do.”

The one surviving sibling said he wished it was him, and not his siblings.

“If I could change places I would.”

The families have asked for privacy.

"I am hoping that now the media will leave us in peace” Mrs Goodchild said. “So we can try and get some semblance of order in this otherwise mad world as our friends and family have pulled together at this terrible time."

"The support that Australia has shown is amazing. It just goes to show that there are a lot of good people out there."