Under Section 541.05 of your state's statutes, you have a six-year statute of limitations, or six years to bring a legal action for theft, or someone taking another's money or property (such as by using a power of attorney to take someone else's money for his or her own benefit). If you are the executor, administrator, or personal representative of your mother's estate, you should have the authority to bring this legal action against the attorney-in-fact or agent (those are the names for the person given power by a POA).