Updated December 17, 2014 01:59:27

Photo: A woman was stabbed in her suburban home hours after she attempted to have her son admitted to a mental health unit. (ABC News: Nicolas Perpitch)

A 52-year-old woman who was stabbed to death in the southern Perth suburb of White Gum Valley had attempted to get her son admitted into a mental health unit hours earlier.

Sources told the ABC the woman took her 19-year-old son to the Alma Street mental health centre in Fremantle on Monday night but it had closed at 8:00pm (WST).

He was reportedly having a psychiatric episode.

She then took him to the emergency department at Fremantle Hospital but he was not seen and left after waiting for some time.

Hours later the woman was stabbed to death in her home on Stevens Street.

The 19-year-old was arrested at the scene and is under police guard in critical condition at the hospital.

Another man and a woman, understood to be the deceased woman's partner and daughter, were also taken to hospital with cuts to their hands and are recovering in Royal Perth Hospital.

Topics: police, white-gum-valley-6162

First posted December 17, 2014 01:34:31