Speaking for the first time since the May 19 accident, her emotional parents told the Herald on Sunday they wanted to warn parents not to make the same mistake.
"We messed it up once and our daughter is gone forever," said Lexie's dad, Titus. "That's why it's important [parents] restrain babies."
"She was our happiness. We were a happy family, she made our family complete," said Mary.
The couple blamed themselves for the tragedy but said they felt pressured to leave their baby unrestrained because there was no space in the car.
The plan was for a friend to drive the family to Auckland so they could buy a new car. The Navacillas, both nurses from the Philippines, were looking for a seven-seater family van for their growing family.
At the last minute, her friend's partner joined the group and there was no room for Lexie's carseat.
Mary sat in the middle of the back seat, with a seatbelt fastened, and held Lexie in her lap. Titus sat to her left and their son Gabriel, 3, was to her right in a booster seat.
"There is no second that we don't blame ourselves. It was only once. We've travelled to Taupo and Hamilton as a family and we always put Lexie in the carseat.
"It was one occasion that we really regret," she said.
Mary was knocked unconscious in the crash, and when she opened her eyes she couldn't move. Lexie had been torn from her arms on impact.
"I realised for a second I wasn't holding Lexie any more and I saw Titus with Lexie and he was shouting 'Lexie, Lexie, Lexie'. She was having seizures at the time."
A friend of the couple travelling on the same stretch of road was the first on the scene.
She took Lexie and Titus to Te Kuiti Hospital, where the baby was airlifted to Auckland's Starship Hospital.
Police are still investigating the crash and it is not known if any charges will be laid. The couple hope their safety message will keep other families from feeling the same grief.
"We have already got a life sentence and we don't want what happened to us to happen to other parents, we don't want them to feel the same pain," Mary said.
"Every day I have to wake up to the reality that my daughter is not here."
Child restraint rules
All children under 7 need to be in an approved child restraint.
Approved child restraints include:
• Baby capsules for young babies
• Car seats for older babies, toddlers and preschool children
• Booster seats for preschool and school-aged children
• Child safety harnesses (used with or without a booster seat) for preschool and school-aged children.
- Source: Plunket, NZTA
