Zion Curney was killed, and his cousin was injured.
Canty was charged with first-degree vehicular homicide, reckless driving, failure to maintain lane, and driving without a license or insurance.
The judge ordered Canty's 15-year sentence commuted to time served, plus two years.
Canty, who was sentenced under Georgia's First Offender Act, is being allowed a few weeks to arrange for the care of her two children before turning herself in to begin her prison time.
"This is something she'll have to face the rest of her life," Zion's mother, Chiquita Curney, said. "I think she's been sentenced to life with the memory of my son's accident."