Raquel Nelson's son was killed by a hit-and-run driver last year when he darted into traffic. The family had been crossing in the middle of the street.
The 30-year-old, who was convicted of vehicular homicide, could have received as many as three years in prison, much longer than the six-month sentence given to the driver.
There has been outcry over Nelson's charges and conviction.
"It's really cruel and a big waste of taxpayer money," said Sally Flocks, founder of PEDS, an Atlanta pedestrian advocacy group. "What is anybody going to learn from this? Raquel lost her precious son."
In addition to a year of probation, Nelson must complete 40 hours of community service.
In an unusual move, the judge also gave her the opportunity for a new trial to try to clear her name. If Nelson is found innocent, her record would be cleared. Her attorney David Savoy said they plan to take the judge up on the offer.
The mother of two surviving children said she's satisfied with the outcome of the hearing.
"I'm ready to go home," she said, adding: "I'm walking out of here. I don't feel like I can be more satisfied."
The death happened as Nelson was attempting to cross a busy five-lane street in Cobb County to get to her apartment after getting off a local bus, Savoy said.
The stop is about one-third of a mile from the nearest crosswalk, so Nelson and her family routinely crossed the middle of the street. She led her family to a median in the middle of the road and as they waited for traffic to die down, her daughter bolted across the street and her son followed. She chased after them when a van struck.
The Associated Press contributed to this report.