Jan,
You 'nailed it', as usual. The Christmas deadline request makes it obvious the lady hasn't a good idea of the time needed for such a project. Perhaps you could suggest a tied comforter of squares or rectangles and show her a picture of one. It would be the quickest--and maybe the easiest way in which to combine different fabrics. If she just wants an adult Linus quilt, it might be the way to go. Otherwise--AFTER the holidays.