LINCOLN, Neb. (AP) — The Nebraska Supreme Court has affirmed the life sentence of a woman who killed her boyfriend’s 68-year-old mother in 2013.

The high court on Friday rejected 42-year-old Shelley Casterline’s appeal argument that the sentencing judge did not follow state law in sentencing her to life for her conviction of second-degree murder in the stabbing death of Virginia Barone.

Investigators say the women had been arguing before Barone’s death. An autopsy shows Barone was stabbed twice in the back and 20 times in the chest and torso.

Casterline’s 24-year-old son, Andrew Casterline, was convicted of first-degree murder and other crimes in Barone’s death and also sentenced to life in prison.