If you are unsure that you possess the legal rights to represent the estate of your mom, please do not move forward. This advice is for your own sake. If your mom resided and passed in a different state than you reside especially. Do not feel you are in a hurry to close the estate. I've processed estates years after the passing of the individuals. Follow the law of the state SHE resided within. An attorney may assist with this determination if you have any concerns.
