B.C. Supreme Court Judge Selwyn Romilly sentenced Gerald Peters of Kamloops, B.C., to four years and five months in prison, less time already served.
Peters pleaded guilty on Monday to the manslaughter of Deborah Joseph, just before his trial for second-degree murder was to begin.
The judge heard Peters was an alcoholic from an early age and stabbed Joseph in the heart in their trailer in October 2012, after the couple got drunk on stolen Listerine.
He heard Peters had no memory of the incident but has since taken steps to deal with his alcoholism.
Peters' sister in-law says she feels for the victim's family and believes the sentence is fair.
"She was part of our family also," says Sherry Peters.
"You know, I was close with Deborah and I miss her also, and my brother in-law wants to move on and he wants to better himself without alcohol being involved in his life."