I gather the judge didn't address the issue of the security deposit in the hearing.
I'd check with a local real estate attorney as to whether keeping the deposit as a penalty for not returning keys is enforceable. If so, the attorney may advise sending her a letter advising her such is the case, noting any other damages, and the re-key charges, etc. Even if you don't have a new address and the USPS doesn't have any new information (presumably all her mail isn't still coming there, so it's a safe bet she filed a change of address with post office), you'd send to the address you have. If you have to sue her for anything else, you'll need a good address.
"Also if she did not provide a forwarding address but I know her place of employment and know who she banks with can I garnish her wages without having to sue her in civil court?"
If you have a judgment for a specific amount, you can garnish for that, sure. But only as to what you have a judgment for.
You need to do your own research on the collection procedures in your state. I gather a FIFA is a proof of judgment in GA so, yes, you'll want one.