This is the Georgia hit and run statute. You can see it for yourself here. It is a criminal offense rather than a traffic offense, and as you can see if you look the statute over, how serious this is depends on what happened.
If the accident caused serious injury or death to another individual, the charge is a felony, and she could face a maximum possible penalty of 5 years of prison if convicted of this crime. In all other cases the charge would be a misdemeanor, which would have a maximum possible penalty of a year in jail and a fine of anywhere from $300 to $1,000.
On a first arrest, the possibility of her going to jail for this offense is just about zero, so long as she makes her court dates and follows the judges directions. If she can afford to retain counsel, she should bring him to her court date. If not, she needs to plead not guilty at her arraignment, tell the judge she lacks the funds to hire private counsel and ask the judge to appoint her a free lawyer.
There are several non-incarceratory plea offer possibilities that her lawyer can negotiate for her if she doesn't wish to go to trial on the case but wants to make a deal to quickly dispose of the matter. On a first arrest, she'd be eligible for probation, for example. It's also possible that she could get the matter reduced to a traffic infraction and thereby avoid having a criminal conviction on her record.