Although you often hear that the majority of recovery for stroke victims is seen within the first six months, I feel there is always hope. New advances and research are taking place and have now proven that the brain can make new "pathways". I have read reports that state even though damaged brain cells cannot be replaced, that unaffected brain cells can take over some functions of the destroyed cells.
Has your mom continued physical therapy? I know it must be very hard to deal with what you are going through, how are you doing?