A teen girl was handed a possible nine-year prison sentence for fatally stabbing a 16-year-old Mount Vernon cheerleader following a school celebration.

The 15-year-old, who wasn’t identified, was given three to nine years of prison time by a judge Tuesday after pleading guilty to first-degree manslaughter last December, the Westchester County District Attorney’s Office said.

The teen stabbed Kayla Green during a large brawl after a parade in Mount Vernon to mark the state championship won by the high school boys’ basketball team.

The deadly event happened in Westchester last April and stemmed from a cheerleading rivalry.

Green, a sophomore, was the captain of her school’s junior varsity cheerleading squad; the defendant was part of an independent cheer club that Green was a past member of.  

The victim was knifed in the stomach and tragically pronounced dead after she was taken to the hospital, prosecutors said.

Judge Susan Cacace spelled out the motive in court Tuesday.

“A long-standing rivalry between two cheerleading squads in the city of Mount Vernon,” Cacace said, according to CBS 2.

The defendant apologized in court before her sentence was determined.

“I am sorry my actions took away a big sister. I am sorry my actions took away a daughter,” the girl said, according to Lohud.com, admitting she made “bad choices” that led to heartache for Green’s loved ones.

Green’s relatives believe the defendant’s sentence and apology were insufficient, the newspaper reported. They argued the defendant would be out of prison in a short time.

 “Her killer gets to get out in three years to live her life, to have family, to have a career. My daughter will never see that,” the victim’s mother Laverne Gordon said, according to CBS 2.

Soon after the celebration to recognize the basketball team’s 12th state title, a huge fight was caught on cell phone footage.

District Attorney Mimi Rocah said the fatal stabbing “left a community devastated.”

“A teenage defendant senselessly took the life of Kayla Green, and in doing so, left a community devastated,” Rocah said in a statement.

“As a family and the Mount Vernon community remain in mourning, I want to reiterate my commitment to working with our vital community partners for meaningful violence prevention and intervention, especially for our youth.

“I know that nothing can cure the pain of losing a child. My Office will do what it can within the bounds of New York’s laws to seek accountability in these cases.”

The maximum sentence the teenager could’ve received was 3 to 10 years as a juvenile offender in New York, the district attorney’s office noted.

She’ll serve her time in a juvenile detention center until she’s 18 when she will then be taken into custody by the state’s Department of Corrections, the district attorney’s office said.