Two men convicted of killing four children in a house fire have also been found guilty of murdering their mother, who died 20 months after the same arson attack.
Michelle Pearson, 37, had "clung on to life" before dying months after her children Demi, 15, Brandon, eight, Lacie, seven, and Lia, three, lost their lives.
Zak Bolland, 26, and David Worrall, 28, were already serving four life sentences - with a minimum of 40 years for Bolland and 37 for Worrall - for the children's murders after they petrol-bombed the family's home in Walkden, Salford, Greater Manchester in December 2017.
The pair, who were high on drink and drugs, launched the fatal attack as part of a tit-for-tat feud with Mrs Pearson's 16-year-old son, Kyle.
After the petrol bomb was thrown into the family home in the early hours of the morning, the Pearsons became trapped upstairs as a huge blaze engulfed the house.
The fire spread so quickly and was so intense that the smoke alarms melted before they had the chance to make a noise, according to police.
Demi, Brandon and Lacie all died in the fire, while Kyle managed to escape the blaze through a window.
Mrs Pearson and her youngest daughter Lia were rescued but the child died in hospital two days later.
The mother suffered 68% burns to her body and spent months in a coma before eventually succumbing to her injuries on 25 August 2019.
Bolland and Worrall both denied the murder of Mrs Pearson and said they had been wrongly convicted of murdering her children.
Both will be sentenced next month.
Bolland's girlfriend at the time of the attack, Courtney Brierley, 23, was convicted of four counts of manslaughter at the first trial and jailed for 21 years.
She admitted the manslaughter of Mrs Pearson.
Detective Chief Inspector Cheryl Chatterton, from Greater Manchester Police's Major Investigation Team, said the case was "heartbreaking".
"All of our thoughts are with the family who have been through such a difficult time and have had to sit through two trials and listen to details on what was a horrific and planned attack," she said.