Is it a break in confidentiality to share information amount someone’s debt?

Yes and no. Creditors cannot discuss debts with third-parties under the PA Fair Credit Extension Uniformity Act. However, you are wrong about your mother's debt. It was NOT your responsibility. This is your mother's debt and is an expense of her estate. The funeral home should file a claim with your mother's estate. You do not indicate whether your sibling is the executor of the estate or even whether an estate was probated. And a funeral home is not a lender. Unless there is a written agreement that payments would be acceptable, the bill is to be paid in a lump sum. You also indicate that the bill is in default. Is it? The funeral home cannot just put a lien on your home. They would have to first get a judgment against you. Is your mother's estate pending in PA? Is the funeral home located in PA? If not, the funeral home may not have been aware of PA law, which applies to original creditors. I can't speak to the laws of states where I am not admitted, but not all states have laws which apply to original creditors like this. You should consult with a lawyer specializing in violations of the Fair Debt Collection Practices Act and PA's equivalent law to see if the law was violated here. If it was, PA allows you to recover treble damages, but rather than sue, you may be able to use that as a bargaining chip. However, if an estate was probated for your mother then the funeral bill needs to be an estate expense.