I would look into brewing a flemish sour, though first you could buy a couple of bottles of the style and feed them to your wife to see if she likes them, I'd recommend Rodenbach.

You may also want to look into some kinds of Gruit (hopless beers). I made a Sage Ale with a wheat yeast that is rather fruity and sour with some wine-like characteristics.

Or, why not just ferment your own Sauv blanc? Buy some concentrate and yeast and go to town, your LHBS should have that and if you make beer you've already got the equipment to make wine as well.