Jack said that the doctors said that some people reject the respirator as something foreign and just subsist on it in a general way, but some take to the respirator right away, to the point where it is dangerous, where the body incorporates it as a functioning piece, and the organs do well, working as they should. It seems she was the former kind of somebody, and despite the living will, they kept her breathing on it. Eventually the family fought like alley cats and decided that yes, her will was what should be, and then they let her go.