A woman who killed her quadriplegic husband after setting fire to his house has been sentenced to more than five years in jail, with the judge describing the crime as a "monstrous act".

Grace Soon, 71, had told police that she killed her husband because she had been frustrated that her husband had spent all his money on prostitutes, homosexuals and transvestites, had wanted her to engage in unnatural sexual acts and that he had given her syphilis.

She had pleaded guilty to the manslaughter of her estranged husband Stephen Chin, 63, after she threw a fire bomb in the bedroom window of his Housing Department bungalow at Daceyville and doused the front fence in petrol, in September 2006.

Justice Michael Grove said Soon knew Mr Chin, who required round-the-clock care, would not have been able to escape the blaze.

"On any view, killing by fire a person whom you knew had no capacity to self mobilise from bed was a monstrous act," he said.