Has your mother seen a health professional about her symptoms? This kind of behaviour could be caused by a number of different conditions but only a doctor could tell for sure and be able to diagnose her so that she could get assistance.

In the mean time, can you have a discussion with her about what you are seeing? Being on the other side, you often don't see the symptoms clearly until you hear it from someone who knows you well. If it is done politely and diplomatically then it can make a huge difference.

Hang in there If she will see a doctor about her symptoms there is help out there.