She was convicted of taking part with 41-year-old Paul Clarke in the murders of Desmond Thorpe and Rosalyn Hunt, the Daily Mail reported.
Hunt, 41, was beaten to death in Ipswich town over several days, with the girl responsible for kicking, punching and stamping on her head.Thorpe, 43, a "vulnerable" alcoholic, was smothered amid fears that he would tell the police about the first murder.
The convict, now 16, of Clapgate Lane, Ipswich, was told she must serve at least 14 years behind bars as she was sentenced at Ipswich Crown Court.A judge said the convict had been brought up "with no real understanding of what is right and what is wrong".
Justice Saunders said she could be "manipulative" and was not acting entirely under Clarke's control, adding: "She found violence funny and entertaining."Clarke has already been jailed for life with a minimum term of 27 years.The teenage girl became Britain's youngest convicted female double murderer after the pair's trial at the court, which ended last month.
