The woman inflicted horrific punishments on the boy, one time tying him to a chair with his hands tied behind his back, because he called her a "motherf*****".
The boy could be heard yelling "let me out, I want my mother".
He lives with anxiety and has a fear of showers now.
The woman reportedly punished her own children harshly as well.
NSW District Court judge Deborah Sweeney said the woman was helped by a 26-year-old man.
She has been found guilty of detaining the boy for advantage, causing a person to take a poison with the intention of causing distress or pain, and assault occasioning actual bodily harm in company.
Judge Sweeney jailed the woman for five years and said "there was a cruelty in the offender's conduct against a vulnerable young boy".
The boy's mother has been sentenced as well and the man who was also staying at the home is serving a minimum 12-year jail term.