Heather Wilson-Duncan testified at her trial that she accidentally shot Barry Duncan in their rural home near Didsbury in 2010.
The couple had been drinking heavily and were arguing over the decorations when Duncan fetched a shotgun and urged his wife to shoot him.
Court heard a 911 tape of Wilson-Duncan telling a dispatcher that she thought her husband was joking and she didn't realize the gun was loaded when she pulled the trigger.
She was charged with second-degree murder, but a jury found her guilty of manslaughter and she was sentenced to four years.
Wilson-Duncan's appealed on grounds that the trial judge made several errors, but the Alberta Court of Appeal unanimously disagreed.