Britain's youngest female double murderer was given a life sentence today for killing her father and a woman in separate incidents when she was just 15.
A judge said Lorraine Thorpe had been brought up "with no real understanding of what is right and what is wrong".
She was convicted of taking part with 41-year-old Paul Clarke in the murders of Desmond Thorpe and Rosalyn Hunt last August.
Ms Hunt, 41, was beaten to death in Ipswich over several days, with Thorpe responsible for kicking, punching and stamping on her head.
Mr Thorpe, 43, a "vulnerable" alcoholic, was smothered amid fears that he would tell the police about the first murder.
Thorpe, now 16, of Clapgate Lane, Ipswich, was told she must serve at least 14 years behind bars as she was sentenced at the Old Bailey today.
Mr Justice Saunders said she could be "manipulative" and was not acting entirely under Clarke's control, adding: "She found violence funny and entertaining."
Clarke, of Mountbatten Court, Ipswich, has already been jailed for life with a minimum term of 27 years.
Thorpe became Britain's youngest convicted female double murderer after the pair's trial at Ipswich Crown Court, which ended last month.
Mary Bell, detained at the age of 11 in 1968 for the manslaughter of two boys aged three and four, remains the youngest female killer.
The youngest girl to be convicted of a single murder was Sharon Carr, just 12 when she killed trainee hairdresser Katie Rackliff in 1992.
The judge said Clarke was the "instigator" in the murder of Ms Hunt, also an alcoholic, although Thorpe "played a full part".
"She was responsible for protracted kicking, punching and stamping on Rosalyn, who was not fit to defend herself effectively from the outset. By the end of those attacks she was completely helpless.
"Far from being sorry, Lorraine appears to have gloried in it, describing to her friends at one stage how she stamped on Rosalyn's head."
Thorpe's father was a "hopeless alcoholic" and "very vulnerable person" unable to walk unaided or do anything for himself, and she was his carer.
"He died by being smothered to death," said the judge.
"The only possible explanation for his death can be the fear that he would go and tell the police what happened to Rosalyn Hunt."
Thorpe was influenced by being in the company of Clarke, the "dominant" member of a group of heavy drinkers, and would try to impress him, said the judge.
But he added: "I don't accept that she was entirely under the control of Mr Clarke. She is someone who can be quite stubborn and wilful and is capable of being highly manipulative herself."
The judge said the case was "exceptional" and said of Thorpe: "Her story is an appalling one."
The court heard that Thorpe's parents split up when she was 12 and she initially lived with her mother before going to look after her father at 13.
Father and daughter would move "from one squalid flat to another", sometimes even living in tents.
"She was spending all her time with middle-aged alcoholics to whom violence had become normal. It had become part of their way of life. The alcoholics fought with each other. They stole in order to get the drink they craved," said the judge.
Thorpe stopped going to school and stopped taking the medication she needed to treat her attention deficit hyperactivity disorder (ADHD).
"Social services were unable to keep track of her. When she was placed in a school, she escaped and went back to her father," said the judge.
All the evidence was that they "loved each other very much".
Through drinking they met Clarke and lived at his flat for a time.
Thorpe was growing up in "totally the wrong place and atmosphere to bring up a young girl", said the judge.
"She has been left with no real understanding of what is right and what is wrong," he added.
"No-one who heard the evidence in this case could doubt for a moment that she has had immense difficulties in her life.
"To describe her upbringing as not being a proper upbringing would be an understatement but it has left her as a violent young woman and a highly manipulative young woman as well."
Graham Parkins QC, defending, said: "Lorraine was vulnerable herself, both physically and in terms of her emotional well-being.
"It was highly inappropriate for this young girl to be playing a role of carer to her drunken and indeed very frail father.
"She never really had much of a chance in life."
Mr Parkins said there seemed to have been "little supervision" of her and she had been "left to her own devices".