A former Skowhegan woman who pleaded guilty last year to her role in the 2013 murder of her brother’s ex-wife in New Hampshire is scheduled to testify against her brother’s current wife, delaying her own sentencing until November.

Michele Corson, 45, a mother of three adult children and former manager of a clothing boutique on Madison Avenue in Skowhegan, pleaded guilty in May to charges of conspiracy to commit murder and conspiracy to hinder prosecution, New Hampshire Senior Assistant Attorney General Susan Morrell said Wednesday.

Corson, who lived on Water Street in Skowhegan, is charged in the death of Amanda “Amy” Warf on March 7, 2013.

Warf, 36, was the ex-wife of Corson’s brother, Aaron Desjardins, 38, of Epping, N.H., who pleaded guilty to murder in May. Aaron Desjardins is to be sentenced in Rockingham County Superior Court to life in prison on March 6, Morrell said.

Warf’s body was discovered by firefighters who were called to put out a fire at an abandoned cement factory in Exeter, N.H.

“It’s alleged that he killed her by slicing her throat, severing the carotid artery,” Morrell said in April 2013. Authorities said Warf was killed at the site where her body was found.

Corson is charged with taking a gun from Skowhegan to New Hampshire to help her brother kill Warf after he asked her in a text message to do so, Morrell said last year.

Morrell said the gun was an automatic .32-caliber German Mauser pistol.

Sarah Desjardins, Aaron Desjardins’ wife, is alleged to have sent the text, according to court documents.

Sarah Desjardins is charged with being an accomplice to first-degree murder, conspiracy to commit murder and conspiracy to hinder apprehension or prosecution. She faces life in prison if she is convicted. Her trial, originally set for May, has been continued until October.

Corson originally was charged by a New Hampshire grand jury with being an accomplice to first-degree murder and also would have faced life in prison. Her sentencing had been scheduled for this month.

That charge was dropped on the condition that she testify against Sarah Desjardins.

“Accomplice to first-degree murder carries with it the same penalty as first-degree murder, which is life in prison without the possibility of parole,” Morrell said Wednesday. “She has agreed to testify against Sarah, and she’ll be sentenced after Sarah’s trial.”

Sarah Desjardins has maintained her innocence.

Corson faces 15 to 30 years on the murder conspiracy charge and seven-and-a-half to 15 years on the charge of conspiracy to hinder apprehension.

Morrell said Corson told investigators that Aaron Desjardins had been saying for months he was going to “gut Amy like a fish,” according to an Associated Press story published in May.

According to Corson, Desjardins gave her this account after Warf was dead:

He ambushed his ex-wife in her employer’s parking lot, using a gun that Corson had brought from her father’s house in Maine to scare her. He forced Warf into her car, then sat behind her, wrapped a wire around her neck and told her to drive to the concrete plant in Exeter.

Once inside the plant, Warf fought to get control of Desjardins’ knife, but he kept it, slit Warf’s throat, poured gasoline on her and set her ablaze.

“She did feel terror and pain,” said Morrell, who told the judge Desjardins’ plot to kill her dated back to 2011, when Warf left him.

Before he killed her, Desjardins asked Warf why she had left him and if he was still the beneficiary on a life insurance policy. In police documents, Desjardins also said his ex-wife was trying to take away their son and that he had plotted with his current wife, Sarah Desjardins, to kill Warf.

Soon after he killed her, Aaron Desjardins got a text from Corson asking whether he had “taken out the trash.” It was code asking whether Warf was dead. Desjardins answered yes and said it was easier than he expected, according to the AP story.