Margaret Tongiatama went for a nap on the day her third child was due - but she and her unborn baby never woke up, leaving behind a shattered young family

A Brisbane woman who went for a nap on the day her third baby was due to be born never woke up, with her death and that of her unborn child shattering her young family. 

Margaret Tongiatama, 38, and her unborn baby Kariya suddenly died on April 11 while she was sleeping at her home, mystifying her loved ones and doctors. 

Her husband Edward said his wife had a medical appointment just two days before the lives of he and his daughters Ayla-Sialei and Zana Mary were changed forever.

That meeting with a midwife 'went well', Mr Tongiatama told the Courier-Mail, with his wife and the baby seemingly in good health.

He had taken a week off work and had been going for walks with Margaret, known as Magz to her friends, to help induce the coming labour. 

On the afternoon the baby was due, they had lunch, after which Ms Tongiatama said she was tired and went to have a lie down.

When he went to check on her 20 minutes later, Mr Tongiatama discovered that his wife was not breathing.

He called triple-0 and began CPR but said 'she was just gone'.

Mr Tongiatama called out to a man skateboarding on his street, who turned out to be an off-duty paramedic.

'He sprung straight into action, found his way into the house and helped me with CPR until the ambulance arrived soon after,' Mr Tongiatama said.

But they were unable to save Margaret.

'We're still going through all of the tests to see what happened to her but it's at a loss,' her devastated husband said. 

The couple had married at short notice on January 6 when Ms Tongiatama's father was struck with a sudden illness. 

They were saving to one day have a big wedding, but when her dad was given just weeks to live they planned it all in just three days so he could fulfil her wish to walk his daughter down the aisle.  

'We organised Margaret's father's funeral and were in Melbourne helping her mother grieve (and) we arrived back at our home in Warner four weeks before Margaret and Kariya's passing.'

Ms Tongiatama's best friend Sialei has organised a GoFundMe for the family. 

She said 'This is an incredible loss not only for the Tongiatama, Alama and Sili Samuelu families, but for all who were fortunate enough to know and love Magz'. 

'Magz dear father also passed only a couple of months ago, and as you can imagine, her family is still grieving this loss.'

The fundraiser organiser added that: 'Family was so important to Magz, and the financial burden this bears on her husband and family is something we would like to help take off their plate.' 

One of the people who donated to the family wrote that 'Magz would always light up every room she was in'. 

'She had a wonderful spirit and will be sadly missed. My condolences to your family at this time.'

Mr Tongiatama said the day his wife and unborn child died was also Sialei's birthday and that Magz had organised a huge surprise for her outside her work.

She also organised many events, flight and accommodation for her big Samoan family.

'This has left a massive hole in everyone's lives,' he said.