'She is clearly the head of this serpent,' the judge said of Teresa Lewis in 2003 when he sentenced her to death by lethal injection, describing her as the mastermind of the cold-blooded murders of her husband and his son as they slept in rural Virginia. Unless the Supreme Court takes up her last-ditch appeal for a stay, Lewis, now 41, is scheduled to die Thursday night at 9. Her case has drawn unusual attention, not only because she would be the first woman executed in the United States since 2005, and the first in Virginia since 1912, but also because of widely publicized concerns about the fairness of her sentence. Lewis waited this week in her prison cell, reportedly soothed by intense religious faith. Her lawyers say her original defense against the death penalty was bungled. They also cite new evidence indicating that Lewis -- whose IQ of 72 is described by psychologists as borderline retarded -- was manipulated by her co-conspirators, who were out to share in savings and life insurance worth hundreds of thousands of dollars. Her partners in the crimes, two young men who fired the guns, received sentences of life without parole in what her lawyers call a 'gross disparity' in punishment. On Tuesday, blocking her only other chance for a reprieve, Gov. Bob McDonnell said for the second time that he would not grant clemency for what he called her 'heinous crimes.' Lewis' guilt is not at issue, but the death sentence is. By her own admission, she plotted with the men to shoot her husband, Julian C. Lewis Jr., 51, and his son, Charles J. Lewis, 25, a reservist about to be deployed in Iraq. Lewis, then 33, met her co-defendants, Matthew J. Shallenberger, who was 21, and his trailer-mate, Rodney L. Fuller, 20, in line at Wal-Mart and, according to court records, they quickly started meeting and hatching murder plans. She became particularly attached to Shallenberger, showering him with gifts, but she had sex with both men and also encouraged her 16-year-old daughter to have sex with Fuller, records say. Lewis withdrew $1,200 and gave it to the two men to buy two shotguns and another weapon. The night of the murders, she admitted, she left a trailer door unlocked. Later, she stood by as the intruders shot the victims with repeated shotgun blasts. As her husband lay dying, court records say, she took out his wallet and split the $300 she found with Shallenberger. She waited at least 45 minutes to call 911. Her husband was moaning 'baby, baby, baby' when a sheriff's deputy arrived and he said, 'My wife knows who done this to me,' before he died, the records indicate. After initially claiming innocence, Lewis confessed and led police to the gunmen. In 2003, she was sentenced by Judge Charles J. Strauss of Pittsylvania Circuit Court; Strauss concluded that Lewis had directed the scheme, enticing the killers with sex and promises of money and showing the 'depravity of mind' that would justify a death sentence. In separate proceedings, the same judge gave life sentences to the gunmen. Lewis' lawyers later unearthed what they called compelling evidence that it was Shallenberger who did the enticing, including his own statements that he devised the murder plan and a prison letter in which he said he 'got her to fall in love with me so she would give me the insurance money.' Shallenberger killed himself in prison in 2006. But prosecutors, in fighting subsequent appeals, said that before and after the crimes, Lewis had engaged in concerted actions to obtain money from her husband's account and then from insurance, showing that she was far more capable than her lawyers now assert. None of the evidence suggesting Shallenberger's dominant role has been presented in court, but it was provided to McDonnell in a plea for clemency, along with details of her limited intellect, her diagnosis of 'dependent personality disorder' and her addiction to pain pills. When he first turned down the appeal Friday, McDonnell noted that appeals courts have upheld her sentence and that 'no medical professional has concluded that Teresa Lewis meets the medical or statutory definition of mentally retarded.' Her lawyers argued in their petition to the Supreme Court that the case should be reopened because her original defense lawyer failed to explore whether her low intelligence and her psychiatric vulnerability would have left her able to plan the scheme. State prosecutors disagreed. Opponents of the death penalty, and others who feel Lewis' sentence is unjust, plan to hold vigils Thursday, including one outside the Greensville Correctional Center in Jarratt, Va., where the execution is to take place. 'She very much wants to live and is hopeful that the Supreme Court will stay her execution,' said her lead defense lawyer, James E. Rocap III, of Steptoe & Johnson in Washington. 'She said she is leaving it in the hands of Jesus.' The defense is waiting for the response from the Supreme Court, on a case that the original presiding judge described as 'greed, lust, lies, all woven into murder-for-hire.' 