Elizabeth Edwards and youngest daughter Katie were stabbed to death in their beds. Picture: Just Giving

The boy and girl, both 15, are accused of hatching the plot to kill churchgoing Elizabeth Edwards, 49, and youngest daughter Katie from a McDonald’s three days before the attack, The Sun reports.

One of the teens — a 15-year-old boy — admitted on Monday murdering tragic Liz Edwards and 13-year-old Katie.

The teenage couple reportedly watched the movie Twilight after the brutal double murders. Picture: SuppliedSource:Supplied

A girl, also 15, has pleaded guilty to manslaughter but denies murdering the pair at Nottingham Crown Court.

The victims were found dead in their semi-detached home in Spalding, Lincs, in April this year.

Opening the case for the prosecution, Peter Joyce QC said of the victims: “They were both stabbed through the throat in their beds at their home.”

Both teenagers, who cannot be identified for legal reasons, are alleged to have planned the killings before carrying them out at the house.

Jurors were told how Ms Edwards and her daughter were both stabbed through the throat in order to damage their voice boxes so they could not make any noise.

Katie was also smothered with a pillow and wrapped in a sheet because the girl “did not like the smell of blood” that had splattered the walls of the bedroom.

Mr Joyce said after the pair launched the “cold, calculated and callous killing” they both had a bath together to wash off the blood.

He told the court how they then enjoyed watching several episodes of Twilight together before they were arrested 36 hours later.

Elizabeth Edwards was a well-known member of her local church congregation. Picture: Just GivingSource:Supplied

The young couple sat emotionless in the dock as the details of the case were outlined to a jury and a public gallery packed full of relatives who wept during proceedings.

The body of 49-year-old Ms Edwards was found lying in bed in her room where she had been repeatedly stabbed, the jury was told, leaving “blood spatters” on the wall, floor, and bedding.

Mr Joyce said a pathologist “found eight sharp force injuries of which five were on her hands, which suggested she may have been trying to fend off her killer.”

Ms Edwards had also been stabbed once in the shoulder, and twice — fatally — in the neck with one blow which “almost completely cut through her windpipe”.

The Crown’s QC added: “The injuries would not have been instantly fatal and there is evidence that Elizabeth Edwards survived for a short time.”

Her daughter was found lying on a mattress in her bedroom with two stab wounds to her neck which suggested “the use of severe force” according to Mr Joyce.

The youngster was also discovered with a pillow over her face.

Mr Joyce added that a post-mortem concluded she died from “bleeding — haemorrhage — and smothering”.

Katie Edwards was stabbed through the throat and smothered with a pillow. Picture: Just GivingSource:Supplied

Mr Joyce said: “The killings happened within moments of each other.

“The mother was killed first while Katie slept.

“They were both stabbed through the throat in their beds at their home.

“On April 12 they met at McDonalds and discussed the plans to kill Miss Edwards and her daughter.”

The jury heard how the boy had four knives in a backpack, including a large black-handled kitchen knife which was shown to jurors.

The prosecution barrister said that the boy had then gone into one of the bedrooms where he “pinned Mrs Edwards down on the bed by kneeling astride her”.

He added there were noises of a struggle and “gurgling sounds while the killing took place”, before a pillow was placed over the victim’s head.

Mr Joyce said: “There were blood spatters on the wall — you’ve seen them, blood on the floor and blood on the bed.”

The boy is alleged to have then checked the victim’s pulse, to make sure she was dead.

He then went into the young girl’s bedroom, while his alleged female accomplice waited in the bathroom, where he stabbed the second victim.

Mr Joyce said: “From post-mortem findings it seems probable that Katie was smothered with a pillow and also from the position of her body she may have tried to move away from her attacker.

“Her face was later covered with a sheet.”

The pair were only 14 when the killings took place, making them one of the UK’s youngest ever couple to be charged with murder.

Speaking at the time of the deaths, Rev Mike Chesher at St Paul’s Parish Church, said of Elizabeth: “I don’t know how we’ll manage without her because she’s just brilliant — such a genuine, committed person of such integrity. It is such a horrible shock.”

A crowdfunding page was set up to pay for the victims funeral.

Mr Joyce said that the defendant had “shown no hint of remorse” since the killings. Both teenagers were 14 years old at the time. The trial continues.

This story was first published in The Sun