WA mum burnt down cheating partner's home

A woman who burnt down her cheating partner's rental home, killing a pet cat and dog inside, has been jailed in Western Australia for two years.

Mother-of-four Veasha Foley had already drunk 20 to 30 beers on the morning of November 9 last year before she arrived at the Leonora property to find her partner having sex with another woman on a mattress on the front porch.

Foley, 30, told a psychiatrist the woman ran off and the pair argued before she called out to check if anyone was in the house and then set a blanket on top of the mattress on fire.

"It was particularly hurtful to her because Ms Foley and her daughter used to sleep on that mattress," defence counsel Tanja Cobden told the District Court of WA, sitting in Kalgoorlie.

She felt it was extremely disrespectful to the memory of her daughter, who died months earlier, and didn't mean to burn down the house, the court heard.

Ms Cobden said her client didn't know the pets were inside and was very sad that they died.