In general, the governmental entity to whom the taxes are owed have a lien against the house.
That tax lien may or may not be paid off during the foreclosure process.
If the taxes are not paid through a foreclosure sale, then it may be possible for the government to pursue your mother's estate, and trace the assets to your siblings.
Your sibling's liability, however, would be limited to the amount of their inheritance.
It is quite likely, however, that the taxes will be paid off during any sale of the foreclosed property.
Answered on Aug 27th, 2012 at 2:32 PM