If she is looking for something meditative, your wife might look at Iaido (Japanese sword drawing). Women tend to be more relaxed in that art, and do much better than guys, generally. Plus, you get to swing a sword, which is always fun...
My wife has been a practitioner and teacher of Chen Style Tai Chi for many years now, and loves it. It is the "original" family of Tai Chi, with strong martial application. Tai Chi is good for general health and is much more applicable than many people think.
Also, I would suggest aikido. Your wife could gain a lot of confidence and enjoyment from the knowledge that she could toss around big lugs that might get lippy.
The best thing would be to have her look into a bunch of different schools and styles, and go with what she feels the best about.
Finally, have you taken your wife to class with you? Are you *sure* she doesn't like the Wing Tsun? Have you told her that she would get an opportunity to beat up on *you*?? That is always a strong motivator, in my book.......worked wonders for me...

.....my wife *loves* to show me new stuff she's learned.....with me being the dummy, of course.....
Peace, and congratulations!!