Legal Question in Wills and Trusts in Illinois

On that date, they are asking the court to close the estate. If you have been given enough information documenting that your grandmother's estate had more liabilities than assets, then you can choose to ignore this. If you have any uneasiness, then you can attend and, hopefully, have any questions answered or, if not answered, voice your concerns. If you have uncertainty, then consult an attorney to review the situation.

It appears that you are a party entitled to notice, and presumably an accounting, so if you are in doubt about the value of the estate, this means you did not receive a copy of the accounting. You should ask the Administrator or Executor for this information. If you don't receive this information, maybe this is a reason to appear in court.