Legal Question in Family Law in Georgia

If DFACS involved the answer is most certainly going to be no.

I can tell you from experience, that unless you go through legal channels to obtain custody, any form is legally meaningless. Your Aunt could come back at anytime and request the children be returned. You can file for Guardianship in Probate Court and this is a relatively simple process if your Aunt agrees. I suggest you meet with an attorney.