Legal Question in Wills and Trusts in Illinois

I am sorry for your loss. Taking the last question first, your uncle's financial assets may have been jointly held, meaning they pass to the survivor, or set up to be payable on death, meaning they would pass to a named beneficiary. If so, the burden would be on you to prove that was not the intent, perhaps that he was unduly influenced or otherwise lacking capacity to make effective decisions. Usually, that is a difficult case to prove unless the facts are significantly clear.

Concerning probate, if you do not sign off on the petition that is pending, a court date will be set and the petition will be granted unless there is opposition at that time. So, if you would go to the extent of hiring an attorney or showing up on your own to oppose the petition or file a counter-petition, then you would not want to sign off at this time. The court would have to decide between competing positions. More facts would need to be known to help evaluate whether your niece is the best person to serve, whether she would prevail.

If you are not going to actively oppose the petition, signing off will help move matters forward more quickly and reduce the expense of administration. The administrator will be under a legal duty to act in the interest of the estate and to provide an accounting of receipts and disbursements.