Aiken County deputies say Mary Todd also told the officers who came to her Beech Island home around 4 a.m. Tuesday that she drank too much before the confrontation.
Coroner Tim Carlton identified the victim as 78-year-old William Todd. Paramedics pronounced him dead in the couple's home.
Deputies say they had never been to the couple's home before for a domestic violence call.
Mary Todd is also charged with possession of a weapon during a violent crime. She is being held at the Aiken County jail awaiting a bond hearing.