And she urged anyone who as deaf or was hearing impaired to make sure they had the alarm systems fitted and check they worked.
The flashing strobe light alarm also connected to a vibrating pad that was normally placed under a pillow so it would wake a person at night.
However, the vibrating part of the system had broken a few months ago and she never got it repaired.
"It was lucky I was lying facing the light and it woke me up."
She said she couldn't smell smoke but got up to investigate. Opening the door from the hallway into the kitchen it all became clear. Flames were coming from the rangehood above the stove.
"I was in complete shock. I had to get my great-granddaughter out, she's only f4.
"If I didn't have that flashing light who knows what could've happened."
As they made their way out neighbours were on the phonecalling for help.
Firefighters were quickly on the scene and contained the fire to the kitchen area.
Fire investigator Craig Bain said the likely cause was a kitchen rangehood above the stove where it looked like an electrical fault had sparked the blaze.
Mrs Marsters and her granddaughter have been staying in a motel since the fire on October 11 while Housing NZ assesses the damage.
"I can tell you having these smoke alarms will save your life."
Whangarei man Kim Robinson, who is the chairman of Deaf Action New Zealand, started a petition in August 2016 after deaf University of Auckland student Dean Buckley was left behind during a fire drill on campus.
Mr Robinson said Mr Buckley's story had caused other deaf people to share their stories, including sleeping through fire alarms in an actual fire in a hotel.
He passed the petition, with 737 signatures, to former Green MP Mojo Mathers, who is also deaf, and she presented it to Parliament.
The petition was assigned to the Government Administration Select Committee. Its report recommended that the New Zealand Building Code be amended so that visual fire alarms are mandatory in public buildings.
It also recommended mandatory visual fire alarms are included in the upcoming reviews by the Department of Internal Affairs and the Ministry of Business, Innovation and Employment of the current rules for fire safety and evacuation.