Ppl in that state needs boatloads of patience and understanding.
  Their skepticism and paranoia levels are over the top. It's
  possible though, but one false step and they regress. We're not
  therapists yet it's possible. How much you're willing to work
  with her (20% of ppl = 80% of issues) or not, is up to your
  patience / tolerance levels. Everybody has a cutoff point, so
  there's no shame in stopping when you hit yours or even long
  before, just to save your own time/sanity.