Trust me SD Bear I can empathize with your situation. My household had those same discussions. Fortunately my wife worked in the mortgage industry in the late 90’s and had some background on this subject. During the peak we did an analysis of the mortgage products that were being used and the total lack of underwriting and her jaw literally dropped open and the weight from my shoulders was lifted along with the nightmares of being pressured into buying into this market.
I guess what I find interesting is that she says you are the only person she knows who thinks home prices are going to tank. I guess to most people on this board that debate is basically over. Now its turning to how much and what will happen to the desirable areas (in that how much will they fall, not are they going to fall). Show her the link on case shiller from this site
Make the point that right now home prices are in the process of falling and work back to the reasons why thats happening using the primer people have pointed out. The best of luck to you I know how it feels.