A New Zealand-born mother whose partner murdered her two children has spoken out over her grief.
Police found the bodies of five-year-old Zaraiyah-Lily Headland and three-year-old Andreas Headland inside a Perth home on October 20 last year.
Their father Jason Craig Headland, 36, had told his partner Anatoria Takiwa he would use their young children as "weapons" to "break her heart into 50 million little pieces" to punish her for leaving him.
Ms Takiwa has spoken out over her pain, asking how she can continue.
"How do you go on from this? I have no idea," she says.
"I don't know what to do."
In the Western Australia Supreme Court on Thursday Headland was sentenced to life behind bars, with a minimum of 31 years to be served for his "grotesque act of family violence".
The court heard that the cause of death could not be ascertained but the children had been drugged with a sleeping tablet crushed in their juice, and asphyxiated.
Justice Lindy Jenkins described Headland's actions as vindictive and the most extreme act of selfishness.
"You made your children pay with their lives in order to inflict pain and loss on your wife."
Ms Takiwa now sleeps with her children's toys to stay close to them, and lives with the guilt of not protecting her children.
She said in her victim impact statement that her children were bubbly and excited to learn, describing them as her heart and soul.
"Two peas in a pod they were, and polar opposites," she said. "They completed each other and they completed me."
Since their murders, she has suffered anxiety and depression, and is scared that if Headland is released he will come after her.
"You make me sick. I'll never forgive you," she said, addressing Headland in her statement.
"What you did was heartless and selfish."
However she says she is determined to stay strong and make them proud.
"I know they wouldn't want me down and depressed," she says.
"They never saw me like that, so they wouldn't want me to be like that now."
NZN / Newshub.