Don’t reorient it just upsets demented people.  Just go with the flow , don’t correct unless absolutely necessary.  Agree, make up stuff, don’t correct.  If she sees people say something general, sometimes I see things too.  Change the channel.  If she is having a conversation with a person not there, comb her hair, get her a cup of tea, turn on her favorite music, turn on a favorite movie.  My mom loves little kids, babies.  On especially bad days I turn on the video of babies and success she is good for a while.  Good luck, make sure you get yourself some help and a break.  Otherwise you will loose your noodle.