gness, I am sorry to tell you this. There is a condition called terminal cachexia where, broadly speaking, the body ceases to be able to make use of nutrients an as with your Mum, may also not be eating or drinking. healing doesn't happen, skin cells aren't replaced, natural skin oils are not made and so on. One of the symptoms of this is the development of pressure sores and, no they don't heal. Sometimes even the best nursing care can't stop it happening. You might now wish to start talking to the Nurses who dress the wound about the Liverpool care pathway. I know there has been much in the news about its misuse; but used properly for the proper reasons it really does help to facilitate a kind and peaceful end where this is possible. Some places will be able to provide pressure relieving mattresses and cushions to make the person more comfortable but some people don't seem to feel the pain anyway because they are too far gone on their journey.