A family fled as their home was gutted in a molotov cocktail attack - carried out to stop the father of the house talking to the police.

Phoebe O'Donoghue, 28, admitted the attack when she appeared in the Nelson District Court yesterday. The unemployed woman pleaded guilty to intentionally damaging a Bunnythorpe, Manawatu, property by fire knowing that danger to life was likely to ensue and wilfully attempting to pervert the course of justice by setting fire to the dwelling of a prosecution witness, the Nelson Mail reported.

The man, who had spoken to police after seeing a burglary, and his wife woke to the sound of breaking glass in April and managed to get their daughters, aged 10-13, out of the house.

The fire caused $450,000 of damage.

Police prosecutor Sergeant Chris Stringer said O'Donoghue threw a lit molotov cocktail through the home's french doors, then walked away as it burned.

"The family are left with little after the home was completely destroyed along with the entire contents," he said.

Judge Tony Zohrab remanded O'Donoghue in custody and she will be sentenced in Christchurch on September 14.