The children were thrown 3m to 4m from the front of the car, he said.
"The risk of serious injury to others in the park was a real risk."
Mr Frost said the car crashed square into the bench demonstrating Jackson's view was completely blocked by the two children.
"She was driving blind," he said.
Jackson's lawyer Jason Owers claimed his client was in first gear the whole time and was not going more than 10km/h. The children were not thrown from the bonnet but rather slid off, he said.
Mr Owers said his client had "absolute regret and remorse" for her actions.
"She accepts entirely the foolishness of her actions," he said. "She accepts she was lucky that there weren't more serious consequences."
He explained that Jackson's partner had died a month earlier and she and the children were still dealing with the grief.
She had taken the children to the park for a treat and succumbed to the children's request in an effort to make them happy after seeing another family doing the same, he said.
Community magistrate Sherida Cooper described Jackson's actions as "quite disturbing" and "very foolish".
"You really didn't engage your brain," she said. "You have taken a real risk and the photos that have been provided indicate that you really couldn't see. It was all around very foolish behaviour. You could've killed somebody else's child. You could've killed your own child."