The family of the pregnant mum who died in Hobart crash speaks for the first time.

On Friday morning, Jane Paino received the knock at the door that every parent fears.

It was the police, telling the Hobart woman her heavily pregnant 24-year-old daughter, Sarah, had been in a “bad accident”.

Sarah’s 24-year-old partner, Daniel Stirling, also received the same terrifying news and both were rushed to the hospital.

There they discovered Sarah had tragically died, but medics had saved her baby boy, who was born at 32 weeks’ gestation and weighed just 2.5kg.

“We saw the beautiful baby and he’s just like Jordan [his big brother] was as a newborn — he is gorgeous with loads of dark hair,” she told News Limited.

“Sarah has left behind part of herself for us all to look after and remember her by.”

Mrs Paino, 51, describes baby Caleb – who is in a stable condition in intensive care – as a “precious gift” in a time of horrific grief.

“Sarah was my whole world,” she said.

“If it wasn’t for Jordan and the new baby, I don’t think I would be able to carry on.”

She said the couple’s toddler son, two-year-old Jordan, who received only mild injuries in the car accident, doesn’t know his mum has died.

“I think he knows something is wrong because his dad isn’t working and his mum isn’t here.

“But how can you try and explain to such a tiny child that he won’t see his mummy again? It’s unbearable.”

Mr Stirling’s mother, Lynda, said she was “so proud” of her devastated son for “being so strong for his kids”.

“We will all help him bring up the boys in years to come,” she said.

An online fund set up to assist the young family has raised more than $220,000 so far.

A Melbourne businessman has also reportedly pledged $100,000 to the Stirling family and actor Brendan O’Carroll, who plays Mrs Brown in TV show Mrs Brown’s Boys, donated $50,000 on live TV earlier this week.

Sarah was just days from her final ultrasound scan, her friend Tiara Barron previously said.

“She was really looking forward to seeing him on the screen and seeing how much he’d developed,” she said.

“She was such a natural mum and loved the whole experience of pregnancy.’’

A 15-year-old boy has been charged with manslaughter over the fatal incident.

You can donate to the family here.