A Brisbane mother who was set alight with her three young children "did everything she could to protect" them from her estranged husband, a friend says.
Hannah Baxter, 31, was pulled alive from the driver's seat of the family car as it was engulfed by flames on a Camp Hill street about 8:30am on Wednesday, during what should have been a routine school run.
Her children - Lainah, 6, Aaliyah, 4 and Trey, 3 - all died inside the car.
Baxter died hours later in hospital.
Her estranged husband and the children's father, former Warriors rugby league player Rowan Baxter, allegedly poured petrol on his family in a suspected domestic violence incident.
Police said he was in the front passenger seat but made it out of the burning vehicle.
He died with self-inflicted wounds on the footpath, police said.
Friend Caitlin Langford said Baxter was "just the most beautiful woman".
"She was kind, and strong, and lit up any room," she said.
"She was the most beautiful mama to her babies and the most inspirational role model."
Hannah and Baxter, 42, ran a fitness business at Capalaba for about five years. Baxter was a champion in trampoline sports and specialised in kids and "Mums n' bubs" classes.
The gym shut its doors late last year.
Friends of the couple told the ABC that signs of the Baxters' lives unravelling were there.
Baxter had moved out with the children, and Baxter was living alone in the three-bedroom Carindale home the family had shared.
Friends said problems in the marriage had been visible for some time.
"She loved them so fiercely and she was doing everything she could to protect them," Langford said.
For the months after the separation, Baxter peppered Facebook with messages wishing his children goodnight, posting pictures of them cuddling together, and telling them he missed them.
A fundraising page has been set up for Baxter and the children's funeral.
Police are expecting to give more details of their investigation into the suspected murder-suicide this afternoon.
'It doesn't feel real'
Korri Lauder, who has known Baxter for more than a decade, said her friend was "the definition of love".
"It's not just her family that's crushed it's the entire trampolining community and gymnastics Australia," she said.
"It doesn't feel real, it doesn't feel like it's her.
"She lived, breathed (her kids). She'd do anything for those kids," Lauder said.
"When you think of family, you just think of her."
Baxter, born in New Zealand, proclaimed he was "one of the top fitness coaches in Brisbane", and his expertise was once bolstered by a video testimonial from rugby league star Sam Thaiday.
But it was another online video of Baxter that provoked the attention of many in the wake of the tragedy.
Last month, he posted a video on Facebook of him play-fighting with his children.
He responded to their playful "attacks" with practised demonstrations of the kind of headlocks used in mixed martial arts, and laughed out loud after slamming toddler Trey's face into a mattress.
"Sweet dreams my babies xo Love you to the moon and back #nowords #dad #myworld", he posted.
Others read something more sinister into the muscular man's rough-housing with the young children.
In the wake of yesterday's tragedy, more than 700 people piled onto Baxter's page to post mostly damning comments under the video.
Arguments raged about whether his handling of the kids in the video represented some kind of warning sign.
The suspected killings of Baxter and her children echo a series of disturbing cases more than four years ago which thrust the protection of women at risk from former partners onto the state political agenda.
The public outcry in response to a cluster of highly-publicised homicides in 2015, including Tara Brown and Karina Lock, prompted moves to overhaul police and government responses to family violence.
The Palaszczuk Government fast-tracked recommendations from Quentin Bryce's Not Now, Not Ever report.
Local MP Joe Kelly was among those who laid flowers at the scene and said he had been "sickened" to hear the news.
"I think this would would rock any community," he said.
"People are being killed by domestic violence every week in Australia and sadly it's now our community's turn.
"We have to continue to work really hard to stop people dying.
"To do that we have to change our attitudes and culture and we have to make sure that we treat people with respect and relationships are based on collaboration, not control."