Aslan, Why make sure she is the last person to know? People with MI still need to be treated with dignity and respect, just like everyone else. I don't really know any adults who enjoy being treated with kiddie gloves.

What is your wife dx with? Or does she have a diagnosis? I think there must be a way to do this and make sure she is safe yet still respects that she is a person first and foremost. If she has a therapist, contacting them as OpenEyes suggested might be a good idea.