Kathleen Dorsett told a judge Thursday she sent 42-year-old Stephen Moore to his death in the backyard, where her father was waiting to kill him, in 2010.
The father, Thomas, said he started an argument with his former son-in-law, then struck him in the head with a cable. Father and daughter then stuffed the body into the trunk of a car, which was burned.
Lesley Dorsett pleaded guilty to conspiracy to commit murder, admitting she plotted to kill her daughter's former mother-in-law to keep her from testifying.
The family members say they were upset they were ordered to support Moore financially.