Can you help me help a friend?

My friend and his mother has a house that they are about to lose due to back taxes. She is disabled (bedridden) and is a senior citizen supposedly exempted from paying house taxes. His name is also on the mortgage doentation. However, she was supposed to complete a form for the exemptions but either overlooked it our didn't do it years ago. She is 74 and again, disabled, and probably has received several notices about this situation. Can she as a senior still override the deed being put into someone else's name or should I say sold to someone else since she wasn't to pay taxes in the first place?