My Grandmother passed away in 2008. In 2009 my aunt received an amended 2007 tax return from the IRS stating my Grandma sold stock and did not report the gain. Since no one responded to the IRS, we now have a tax lien against my Grandma.

What are her options? Is she responsible for my Grandma's IRS debt? Also,
there was no estate or probate, everything went to my uncle.

Just a note: My uncle actually received all the money from the sale of the
stock, but he thinks the debt should be split among the heirs.

Thank you, Tammy