What would you say to your wife if she disgraced your mother?

I think the best way to approach the conversation with her would be calming down first, then telling her that you really don't appreciate her discussing your family business in that manner. Also explain to her that your mother isn't replacing her as the woman in your life because nine times out of ten she is feeling anxious about your mother coming to live with you guys on a permanent basis. She just needs to be reassured that her feelings are first and foremost with you as they should be considering she is your WIFE. However, explain to her in a firm but gentle manner that disrespect will not be tolerated from her or your mother and then be sure to give your wife some extra time with you once your mother arrives cause she is going to feel smoothered by your mothers presence in the home. But before you do any of these things be sure to calm down as to avoid what could turn into a very heated discussion causing you to find out some feelings your wife has that you had no clue about.