Is there any legal action we can take against our sister's conservator?
In all likelihood you and your sister should have been notified of your other sister’s conservatorship. While the notification requirements vary by state, most provide that immediate family members should be notified. If, for whatever reason, that did not include you as siblings, it most certainly should have included your sister’s son or his caretakers.
A conservator is a fiduciary—that is, someone who acts on behalf of, and in the interest of, another person. If your sister’s conservator mishandled your sister’s or your nephew’s funds, you should be able to take legal action based upon her conservator’s breach of those fiduciary duties. In addition, if the conservator was appointed based upon fraud—a failure to notify your sister’s family and any assertions of the right to appointment that did not disclose the existence of family members—and the conservator received payment for his or her services, that may give rise to an additional cause of action.
Keep a few things on mind as you move forward. For one, there is likely a statute of limitations that prevents you from bringing an action against the conservator after a certain amount of time has passed. These statutes usually range from one to three years, and the particular applicable statute will depend upon your deceased sister’s state of residence. In any event, swift action is probably in order.
In addition, there may be restrictions in how an action may be brought against the conservator. In your sister’s state, the law may require that the executor or administrator of her estate bring any action against the conservator, or your sister’s heirs or their representatives, in the case of your mentally impaired nephew may be the ones to rightfully bring the action. You and your other sister may not be able to bring the action yourselves, at least not in your individual capacities.
Last, there may be state agencies that should be involved or notified. If your sister’s conservator is a private professional fiduciary, most states require that these individuals must be licensed, and if this is the case in your sister’s state, the licensing agency should be notified. Even if your state does not have licensing requirements, there may be a consumer affairs department or adult protective services agency that has jurisdiction over cases in which a private fiduciary breached his or her duty.