I do not practice law in Georgia,, and so cannot advise you about the specific procedures you will need to follow.
Every state has a procedure by which an uncooperative executor can be made to do his or her job. I will assume that the will has been admitted to probate and the court has made the appointment of the executors, and that the deceased did not leave any creditors who need to be paid with the assets.
If you have not already done so, send a letter (certified mail, return receipt requested) to your sister POLITELY telling her that as the executor, she is legally required to follow the instructions stated in the will and setting a deadline by which the assets are to be distributed. If the deadline passes without any action, take a copy of the letter and proof of mailing and consult with a local probate attorney about the appropriate next steps.
It sounds as if the will has not yet been offered for probate. If so, either the will or state law generally provides as to what is to happen when one of two named co-fiduciaries is unable or unwilling to act. In either event the "willing" sister should file a petition to have the will admitted to probate. As far as the assets in the hands of the recalcitrant sister are concerned, the executor of an estate has a duty to "marshall" the estate assets and if the assets are not surrendered willingly, the court may enter an order requiring the assets to be surrendered.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship
If you are also a beneficiary, you can petition the court to order the estate be distributed. Any beneficiary can file a petition with the probate court to order the distribution of the estate. If you are the innocent executor, make sure you have plenty of written communications to support the fact that you continue to attempt to distribute the estate . You can also file a petition to remove teh executor who is uncooperative. The will then governs whether the innocent executor can serve alone.