A mother has been found guilty of smothering her young children and hiding them in the boot of her car in an attempt to hurt her ex-partner.
Fiona Donnison killed three-year-old Harry and Elise, two, to punish their father, Paul Donnison, a court heard.
She has been sentenced to serve a minimum of 32 years in prison.
The prosecution claimed she stashed her children's bodies in her Nissan in order to lie in wait for her ex armed with two knives, but he never arrived as he was staying with his new girlfriend.
Donnison, 45, who adopted her partner's name by deed poll without telling him, walked into Heathfield police station on January 27 to tell officers she had killed Harry and Elise.
She had superficial cuts to her wrists and had taken a number of Nytol sleeping tablets when she arrived at the station but would not tell the police where the bodies were.
A search revealed the children had been placed in separate holdalls in the boot.
The day before the murders Donnison went to court to try and force her ex partner to move out of the family home, but was told this could take time.
The defence said she was not in her right mind when she killed the pair, as she had been severely depressed, and argued the charge should be reduced to manslaughter.
But one clinical psychologist said Donnison was "100% likely to be feigning" her mental health problems. She was also described as controlling and narcissistic.
The prosecution said the level of planning involved warranted a murder conviction and a jury at Lewes Crown Court unanimously agreed.
Mr Donnison, 47, broke down in tears in court as he described the last time he saw his children.
"Harry was in his pyjamas and he came over and wrapped his little arms around me and we hugged and I gave him the toy and I was kneeling down.
"He had his arms around my shoulders and my neck and I was cuddling him.
"And Fiona was standing two or three feet away with a look of absolute hatred and evil on her face. Harry was then shooed back into his bedroom.
"That was the last time I saw him alive," he told the court.
"I then went to Elise's bedroom and she was peacefully asleep. I gave her a peck on the cheek, she just wiggled her nose. She didn't wake. And that was the last time I saw Elise," he added.