Jackson said at the time of the murder, she was on medication for psychosis and depression.
Jackson previously told the court she stabbed Walker several times with a kitchen knife, waiting half an hour to make sure she was dead.
Michael Walker met Jackson on a dating website in 2014, telling her his "deepest desire" was to get rid of his wife as he couldn't divorce her for financial reasons.
Jackson revealed that the pair had a texting code for the night of the murder.
Michael Walker was sentenced to 35 years in prison for conspiring against his wife with his mistress. Photo / Facebook
He would text her the word "good", meaning Jackson could break into the house via a window, or "bad", meaning she'd have to use the key to get in.
Jackson told the court she "went inside and grabbed a knife and went upstairs and stabbed her".
After he was sentenced, Walker apologised to his wife's family.
"I love Cathy very much and I would do anything if it could bring her back," he said.
In 2016, a military court found him guilty of child pornography charges that came up during the murder investigation.
In 2017, Walker was convicted of sexually abusing a child, physically assaulting a child, and wrongfully communicating a threat.
