I would suggest not to give up on your wife if she is willing to try an int'l trip, however reluctantly. Her first trip might spark some courage, and if not in the future she will beg you to go w/o her .

Try a place that doesn't use up too many miles (they end up being wasted if your wife hates the trip) and doesn't involve very long flights. I suggest France, Spain, Ireland, maybe a few of days in England. Nothing TOO exotic (I consider Turkey, Greece in this category - travel newbies aren't comfortable w/vendors coming up to them, general chaos, etc.). She might be made uncomfortable by the poverty of Mexico, Peru, etc., plus she has to drink bottled water, no ice, etc.