Cherelle McKenzie-Jackson was found guilty of the manslaughter of Junior Nkwelle, 15, as was her 17-year-old boyfriend Marc Anthony Tulloch last month.
Tulloch, of Herne Hill, south London, was ordered to be detained for 10 years.
Old Bailey Judge Richard Hone lifted an order banning identification of the defendants in the hope that their sentencing would be a deterrent to knife crime.
He said the pair were cleared of Junior’s murder after the jury found they had not intended for him to be seriously harmed.
Judge Hone told McKenzie-Jackson that it was only her age which saved her from the same sentence as Tulloch.
He told her: “You seem physically and behaviourally older than your biological age.
“You made threats after your argument with Junior Nkwelle that were described as ‘going ballistic’.”
The judge described the girl as “troubled”.
She had been living with her grandmother on the Loughborough Estate, Brixton, south London, because her mother could not cope with her behaviour.
She had spent over an hour on the phone to Tulloch persuading him to deal with Junior after she said he had disrespected her when she interrupted his game of football on the estate.
Tulloch, who was then 16, was either handed the knife by her when he arrived, or had brought the knife with him in September.
Junior and his friends had been playing football on a grassy area but the girl and her friends appeared to have taken offence.
He was stabbed through the heart after Tulloch arrived on a bus and started fighting with him, and died on the makeshift pitch.
Jonathan Turner, QC, prosecuting, said it was likely Junior and his killer did not know each other and there was no quarrel between them.
Mr Turner said: “Marc Anthony Tulloch was telephoned by his girlfriend and told to come to the estate to teach Junior Nkwelle a lesson.
“There had been an argument between her friends and Junior’s friends whilst the football was going on.
“She thought that Junior had insulted her or been less than respectful to her.
“She was very angry and determined that he should be punished – indeed stabbed – to put things right.
“She called up her boyfriend and was heard to tell Junior that she had arranged for somebody to come and stab him.”
Mr Turner added: “He was encouraged and requested by her to come and do this.
“Indeed, to use an old-fashioned phrase, was ‘set up’ by her to do this.”
Junior’s mother Stella said in a statement that she still could not come to terms with his death.
She said: “It doesn’t make any sense to me. It happened so quickly and so close to our home.
“I didn’t even know what was going on and I had no chance to help, or see him and say goodbye and tell him how much I love him.
“By the time I got to him my poor child had bled to death.
“I can only describe Junior as a kind, friendly boy who always had a smile on his face.
“He was a fantastic footballer and a great student who loved school.
“He was a good son and a wonderful companion, brother and role model to his younger brothers.”
Detective Chief Inspector Charles King said: “This death illustrates the terrible consequences of the casual acceptance that knives have a part to play in minor disputes between young people.”
There have been a series of deaths caused by knives in recent years and the authorities are working to try to raise awareness of the danger.