The mother of toddler Liam Fee has been jailed for his murder along with her partner.
Trelfa, 31, who is also known as Fee, was jailed for life in Edinburgh and ordered to spend a minimum of 24 years in jail while her civil partner, Nyomi, aged 29, was sentenced to 23-and-a-half years.
Liam suffered terrible injuries to his heart
A court heard how the couple abused and neglected Liam for most of the two-year-old's life.
He died from a blow to his abdomen at his home near Glenrothes, Fife, on 22 March 2014 resulting in heart injuries described as similar to those found on road crash victims.
The pair, originally from Ryton, Tyne and Wear, were convicted of Liam's death following a seven-week trial at the high court in Livingston.
Liam was subjected to "unyielding, heartless cruelty"
They were also found guilty of horrific cruelty against two boys in their care, one of whom they tried to blame for Liam's death.
Judge Lord Burns told the couple they had subjected the children to "a cruel and pitiless regime of ill treatment and neglect".
"In the case of Liam, that treatment included the assault which caused his death."
The pair showed no emotion on hearing their sentences
The post-mortem examination, he added, showed Liam had been "subjected to a prolonged course of violent behaviour".
The case, described as one of "unyielding, heartless cruelty" was one of the worst ever heard in a Scottish court - some jurors were in tears as they heard evidence.
Jurors heard that there had been an increase in violence towards the blond-haired, blue-eyed boy leading up to his death, including the pair not getting help for Liam when they knew he had a broken leg and fractured arm.
Their "callous indifference" to his injuries would have left the child in agony, but the killers did not seek medical aid, looking online instead to see "how do you die of a broken hip" and "how long can you live with a broken bone?".
The couple showed little emotion as they were told how long they would spend in prison.
Liam's father, Joseph Johnson, who was in court, looked straight ahead as the sentences were handed down.