Virginia to execute woman later this month for the first time in nearly a century.

The state of Virginia plans to execute a woman, 41-year-old Teresa Lewis, a grandmother with such a low IQ that she’s classified as borderline mentally retarded. Lewis is set to die by lethal injection on Sept. 23. She’ll be the state’s first female prisoner put to death in 98 years.

Lewis pleaded guilty to hiring two men to murder her husband and stepson in their trailer in Virginia’s rural Pittsylvania county in 2002, in order to collect life insurance money. She took cash from her husband Julian Lewis’ wallet as he lay dying from gunshot wounds and waited 45 minutes to call police, The Virginian-Pilot newspaper reported. But when sheriff’s deputies arrived, Julian was still alive and told them:

“My wife knows who done this do me,” ABC News reported.

Lewis husband died soon after. The two triggermen, one of whom Teresa Lewis was having an affair, got life in prison. According to Time magazine, a judge deemed Lewis the crime’s mastermind and called her “the head of this serpent,” and sentenced her to death.

If Lewis’ sentence is carried out, it would be the 12th execution of a woman in the U.S. since the death penalty was reinstated in 1976. The woman’s lawyers are arguing for clemency, saying that essentially, she’s too dumb to execute. The U.S. Supreme Court has ruled that executing a mentally retarded criminal violates the Constitution’s 8th Amendment, which prohibits cruel and unusual punishment.

But Virginia doesn’t consider someone mentally retarded unless they score significantly lower than average on IQ tests, and also struggle to function in society. Lewis’ IQ has been measured as low as 70, but the Virginia Supreme Court and a federal appeals court have both rejected the notion that she can’t function normally in society.

Her plight has been taken up by Christian groups and a longtime prison chaplain, the Rev. Lynn Litchfield, who befriended Lewis behind bars. Litchfield wrote in a letter to the governor last month, excerpted by the Virginian-Pilot:

“It is my sincere belief that Teresa Lewis’s life has merit to the Commonwealth of Virginia.”

“She can be a positive force for good within the prison system helping other incarcerated women.”

Litchfield and other advocates have set up a website, SaveTeresaLewis.org, listing reasons why Lewis’ life should be spared. They cite her apparently strong Christian faith, and how she’s said to calm fellow prisoners by singing country gospel songs that echo across their prison cells.