The mother of a man who was fatally stabbed by an "impulsive" heroin dealer with a $400-a-day habit is furious that her son's killer could be free in less than five years.

Zoe Giannioudis, 31, stabbed Simon Cartwright, 38, on October 30, 2017, after an ongoing feud while she was dealing in Victoria Street, Abbotsford.

Zoe Giannioudis arrives at the Supreme Court for sentencing on Thursday. Credit:AAP

The "severely addicted" woman was sentenced to an eight-year prison term in the Supreme Court on Thursday, with a non-parole period of 5½ years.

"I'm appalled," Mr Cartwright's mother, Tracey, told reporters outside court.