How cool! Your wife sounds kinda like me! I seriously thought I was the only woman like that; who didn't like porn at all, but liked certain types of erotic stories.
I am a writer so I often see those stories in places I'm trying to get published. I came across a ton last night, but will have to find the site. The only thing is, I have a hard time because a lot of the stories I come across end up being something too extreme for me like one story was sounding really good until I read where this guy was using his home as a dog shelter where he would get under age girls to come have sex with his dogs while he watched! So it ends up being a waste of time and a real turn off and I get frustrated. I also have found a lot that I would like, but it seems that online they're always taken to extremes that turn me off or freak me out like rape. I read a guy's multiple stories (true) about how he raped women. Not cool!
I have yet to find one that didn't involve murder, rape, or animal sex. I like just nice, soft and a little romantic stuff. Maybe I'm the weird-o?
Your best bet would be to look up online mags under romance and usually most of them have an erotica section if she's not into hardcore or extreme stuff. A lot of the romance mags that I came across during my school work last night had tons of what seemed to be a nice variety of erotic stories on the softer side or more realistic side. It's also easy to find hardcore. I will try to remember those sites. I was in the middle of school work so I didn't get the chance to read much of the published works on erotic lit, but it's out there. I'd just type it in a search engine with your preferences i.e. soft, sensual, romantic, hard core erotica, gang banging erotica, etc. That way, you'll be more likely to find what you're into.