The grandmother of two young children found dead in their Perth home has paid tribute to her “cheeky monkeys”.

The woman, who wants to be known as Georgina, said her three-year-old grandson and five-year-old granddaughter “were gold, they were more than gold to me”.

The bodies of the children, together with their injured father, were discovered by officers who forced their way into the home on Flight Vista in Yanchep, in Perth’s north about 10:30pm on Thursday.

Their 35-year-old father, who is Georgina’s son, remains under police guard in a Perth hospital in a critical condition with self-inflicted wounds.

Police would not reveal how the children died, but said they were “not looking for an unknown offender”.

Georgina is yet to see her son.

“We haven’t had any contact as yet but we’re just sort of hanging in there because there is another older daughter that we’ve got to stay with … she’ll be 16 next week so we’ve got to be around her, support her, and ourselves,” she told the ABC.

Relatives say the couple had marriage issues, and the two families had been in discussions about the children.

The bodies of the children were discovered by police officers at the family home.

‘Where do we go from here?’

Georgina said she would never get over what happened.

“It’ll take me until I die to get over this and you know, his brothers and sisters, we don’t know what to say any more,” she said.

“When you face it and it’s real, it just hits you and especially with two little ones … where do we go from here?”

Georgina implored those feeling depressed to seek help.

“If you’re having problems, if you’re feeling depressed please, please go talk to someone about it,” she said.

Detective Inspector Clements said the mother of the children was distraught.

“We have a family liaison officer who has been appointed. We are in direct contact with her now,” he said.

“Obviously [she is] very, very distressed so we are doing what we can at this point in time to provide support, not only to her but to the police officers who attended.”

Police declined to say what led them to the house, and said the events which led to the children’s deaths were forming part of their investigation.