Six months is a relatively short sentence and how much of it she actually serves depends on a couple of factors specific to county jails in Georgia.
The standard expectation going in is that she will serve the full six months. County jails do not have the same good time credit structures that state prisons operate under, and short sentences at the county level are generally served as imposed without the kind of systematic early release mechanisms that exist in longer-term state facilities.
The one exception that does happen at county jails, including those in Augusta and the surrounding Richmond County area, is early release due to overcrowding. When a facility exceeds its capacity, jails have procedures for releasing low-risk, non-violent inmates ahead of their scheduled release date to create space. If her offense was non-violent and she maintains good behavior inside, she could be among those considered for early release if the facility reaches that point.
There is no way to predict whether overcrowding will become a factor during her specific six month window, and it is not something that can be requested or applied for. It happens when it happens based on the facility's population management needs.
What she can control is her conduct inside. A clean record with no infractions, cooperative behavior with staff, and engagement with whatever programming is available puts her in the best possible position if any early release consideration does come up.
In the meantime, staying connected through letters, calls, and visits makes the time more manageable for both of you. InmateAid can help with letters and photos if you want to keep something arriving regularly.