Sandra Layne was found guilty March 19 in the May 2012 shooting death of Jonathan Hoffman during an argument at her West Bloomfield Township, Mich., home. She also was found guilty of possessing a firearm during the commission of a felony.
Layne claimed self-defense, but prosecutors said she stalked the victim around the house before shooting him six times, intending to kill him.
Oakland Circuit Judge Denise Langford Morris ordered Layne to serve an additional two consecutive years for the firearms violation, so she will not be eligible for parole until she is 97, The Detroit News said.
Her attorney has filed an appeal to have the conviction overturned, the newspaper said.
"What's troubling is why didn't you call police first, before you walked up the stairs, before you put the Glock in your hand?" the judge said Thursday. "You could have called the police and they would have come."
"I'm sorry," Layne told the judge. " ... I made mistakes, terrible mistakes.
"I don't want to die in jail," she said. "I don't want to die in prison. Oh God. I'm so sorry. I don't know what to say."
The victim -- who had a history of drug abuse and legal trouble -- had been living with his grandmother for about a month, expecting his mother to join him, but became upset when he was told his mother would not be coming, the newspaper said.
Layne testified during her trial she shot Hoffman in self-defense after he assaulted her during an argument.