A 15 year old boy has admitted murdering Elizabeth (pictured above left) and Katie Edwards (right) in Spalding, however, his 15 year old girlfriend denies murder but has admitted manslaughter.
Police discovered the bodies of Elizabeth, 49, and her 13 year old daughter, Katie, at their home on Dawson Avenue on April 15th, this year.
Prosecutor Peter Joyce QC said Elizabeth, a dinner lady, was found lying in her bed where she had been repeatedly stabbed, including in the throat, and blood stains were left on the wall and floor.
Joyce said her daughter was also stabbed in the throat while in bed and a post-mortem examination concluded she died from bleeding and smothering.
Child psychiatrist, Dr Indranit Chakrabarti, told Nottingham Crown Court a medical condition had diminished the 15 year old girl's ability to exercise self-control, however, Joyce refuted the claim, saying she had acted in a "logical and cold" way.
Dr Chakrabarti, believed the girl had intended to kill both victims but added: "Yes, there was planning. I do not think the planning was the result of her forming a rational judgement."
The court also heard the defendants slept together and watched films after the double killing, and had planned to take a bath together.
The trial, which will continue on Thursday, also heard that the girl told police she had intended to kill herself after the killings.