The 27-year-old Oak Flats mother alerted her family and friends in the early hours of yesterday, and a bedside vigil was set up.

Her brother Justin Yerbury said the motor neurone disease sufferer died peacefully at 6.30am, surrounded by her loved ones.

"She was having trouble breathing over the last few days but when she woke in the night she knew it was time and managed to call us," he said yesterday.

Only six years ago their mother died of the same illness. Their grandmother and two cousins have also been lost to the incurable disease.

Mrs Turk was diagnosed in August with the extremely rare familial form, and swiftly went from being a fit young woman who ran every day, to being reliant on expensive breathing apparatus.

The equipment was purchased with funds raised by the Illawarra community - fundraising that also paid for special ramps to be put into her home and for support to be provided to her family.

She left behind Logan, 4, Hannah, 2, and husband Jason.

When diagnosed, Mrs Turk had to turn down a new role in the Air Force and her husband took leave from his job in the Navy.

Mr Yerbury wanted to acknowledge the community that had rallied behind the family and provided "amazing" support - from raising around $160,000, to helping out around the house.

The oldest sibling described his "little baby sister" as someone who loved life, who would do anything for anyone and have a go at everything.

"She would always have a laugh, she was the laugh of the party."

Before she got sick Mrs Turk loved to go out dancing with friends, and used to play basketball for Illawarra.

The former Oak Flats High School student studied mathematics at the University of Wollongong. When her husband got a job in the Navy they moved to Cairns for a period, before Logan came along.