If there is some issue between the amount stated in the affidavit regarding the collection of the small estate and approved by the probate court and the actual amount of money remaining in your sister's bank account with the bank, the affidavit clearly can be amended.The best way is to submit another petition to the probate court for determination and an order based upon a requested hearing. Assuming the court hearing goes forward and an order is issued clarifying the discrepancy, obtain a certified copy of the order issued by the court clerk and have it served upon the bank's representative.Its service should rectify the problem and allow you to get the probate closed, all creditors paid off and the moneys released from the bank to those who are entitled to such.Good luck.