Zekester is correct. Missouri recognizes ANY valid permit issued by any other state. If your friend moves here and has a GA permit, she can carry on that permit until such time it is no longer valid.
Now, if GA laws are anything like we have in Missouri, then the permit will become invalid as soon as your friend becomes a resident of another state. If/when the permit becomes invalid, your friend will have to either obtain the MO permit or a non-resident permit from another issuing state. To carry a concealed firearm in Missouri without a valid permit is a Felony.