CHICAGO — A Chicago teenager whose mother handed her a knife she used to stab to death a 15-year-old girl has pleaded guilty to second-degree murder.

The teen, whose name is withheld because she was charged as a juvenile, is in the custody of the state Department of Juvenile Justice. Cook County State’s Attorney spokesman Robert Foley said Monday the girl can be held until she turns 21.

The teen was 13 years old in May 2016 when she was charged with first-degree murder for stabbing De’Kayla Dansberry in the chest.

Prosecutors say Dansberry was walking with several friends when they exchanged words with the other girl and her friends. The two sides traded punches before Tamika Gayden handed a knife to her daughter.

Gayden pleaded guilty in December to involuntary manslaughter and was sentenced to four years in prison.