The first thing that you need to review is the loan agreement and the security agreement on the family home with the lender. Your mother who received 50% of the family home was entitled to use her share in the home to obtain a loan. The issue is whether or not the loan that she received exceeded 50% ownership in the property.I suggest that you consult with a real estate attorney to review the documents concerning your mother's loan where the family home was used as security to make sure she did not obtain a loan at the time exceeding one half of the value of the home.