I believe that social security benefits are exempt from garnishment. Other assets and property, however, are subject to levy. You will be held responsible for this debt, and you will mostly likely be sued at some point.
I recommend that you speak with an attorney, and see if some arrangement or agreement can be reached. If this is not dealt with properly, a claim may be made against your estate for the full amount, and could cost your beneficiaries.
Social Security cannot be garnished, but the possibility of a garnishment meanst that there is a judgment.
Judgments are filed in the office of the clerk in the place (jurisdiction) where the suit was filed. They can be filed in other jurisdictions as well by being recorded in additional clerks offices.
The judgment gives the judgment holder the right to use various means to collect the judgment. The two most familiar are wage garnishment and freezing bank accounts. The judgment can also constitute a lien on any real property that is in your name. The judgment can sit in the Clerks office for many years, accumulating interest until you want to sell a house or refinance the mortgage on a property, and then title or the loan cannot be secured unless the judgment is paid off.
Disclaimer: This answer does not constitute legal advice. I am admitted in the States of New York, New Jersey and Massachusetts only and make no attempt to opine on matters of law that are not relevant to those three States. This advice is based on general principles of law that may or may not relate to your specific situation. Facts and laws change and these possible changes will affect the advice provided here. Consult an attorney in your locale before you act on any of this advice. You should not rely on this advice alone and nothing in these communications creates an attorney client relationship. The opinions expressed herein are those of the author only and the fact that he has worked as an Assistant District Attorney; State Supreme Court Clerk; Special Assistant United States Attorney (Hawaii); Assistant Cornell University Counsel or Judge Advocate, United States Marine Corps should not be relied upon to assume that these statements reflect the policy of these organizations.