Revenge and retribution are not the same thing. Retribution is getting justice so the person feels made more whole. Vengeance/revenge is destroying the actor who committed the action.
We don't have a society that rehabilitates other, we only have a system that jails people, and unfortunately for her, that is what I think should happen.
Yes, I know that gross negligence has a legal definition, and I'm using it specifically in this case because a CPS worker negligently left a child in her hot car for hours while she went on personal errands. All she had to do was look in her rearview mirror to see the child. Put a sticky note on the fucking steering wheel. She could have done a number of things differently to ensure the child's still alive.
As for atoning for this person's mistakes, they can atone from jail, where they can also serve out community service. Ultimately, this is for a court to decide which I think is the most appropriate as I don't think we'll see eye to eye on this one.
For instance this would have made a significant difference
In the report, NSC also issues recommendations for parents and caregivers including leaving a purse or cell phone in the backseat so they are reminded to check the back before leaving the vehicle.
https://www.nsc.org/newsroom/just-21-states-protect-children-hot-cars
You're also wrong that parents aren't often charged. According to this study, 58% of parents who leave their child in a hot car face charges after the fact.
They also note authorities pursued criminal charges in 58% of cases.