Dad died without a valid will

You should have received a copy of the entire petition, so I hope that's what you were sent, and not just the pages you need to sign or initial. I am also going to assume that your father had his primary residence in Georgia and his estate is being opened in a Georgia county; if not, my answer will likely not be correct. If you don't sign, your mother will still be able to file the Petition and will likely still be appointed as the Administrator unless you challenge her Petition and are successful. However, when she files without your signature, you will be served with notice. If you live in the state where the estate is being opened, you'll likely be served in person, with a sheriff showing up at your door. If you live out of state, you'll likely be served by certified mail. Your mother, if appointed as Administrator, will have to post a bond and file an inventory and periodic reports with the probate court, where if all heirs had consented she could have the bond, inventory, and reports to the court waived (she'd still need to provide information about the estate to the other heirs). You should not sign anything without consulting an attorney or having a complete copy of any Petition. Even if you decide not to sign the Petition, you have rights to the estate's assets as an heir, and you will need to decide whether you want to protect those rights or not. Your mother may file a claim for year's support, which could defeat your interest in the estate if you don't challenge it. Finally, even if you decide that you don't want anything from your father's estate, if you are willing to sign you can make things easier on your mother and less costly and time-consuming. If you don't sign, it means the estate administration process will be more difficult than would have been necessary if you'd been willing to consent to certain things and sign the documents. But it is up to you what you want to do. No one can make you sign or even respond if you don't want to.