Lots of good comments here, but keep in mind that all spouses are not the same. Note that I said that in a gender neutral way, because it's true. I met a lady at OSH several years ago who is the pilot in the family--the bug really caught her, and not her husband. He flies with her, but he's basically the steward along for the ride, digging snackies out of the cooler--he has no interest in becoming a pilot. They fly a 182.
Another couple I know well are both pilots, but she's the real pilot in the family--he hardly stays current, but he makes a good autopilot when she needs to look more closely at a chart. Their over-equipped Arrow has all the bells and whistles one might want in a small GA airplane, and she knows how to use all of it. She's almost fanatical about flying--he'd rather watch.
I've been through the marriage/divorce ringer 3 times, and current SO has been my bestest companion for coming up on 15 years; I'll get to her flying disinterest in a moment.
Wife 1 soloed while we were still in Alaska, shortly after I received my private. She enjoyed flying, but she wasn't interested in pursuing a certificate. We traveled all over the country in our 182 and later the TR182 for many years, 2 adults, 2 small kids, large dog, and a parakeet. The kids were 2 and 6 when we first started flying as a family. She made an outstanding auto-pilot, able to hold heading and altitude as well as anyone.
Wife 2 took the AOPA Pinch-Hitter course, but beyond occasionally holding the controls, she wasn't interested in learning how to fly--but over our 10 years of marriage, we did a lot of traveling around the country with our respective kids, principally in the 231 that I flew for a friend, and occasionally in various rentals and borrowed airplanes. We first met when I picked up her and her then 4 year old daughter at KAPA (now Centennial, then Arapaho County) on a date arranged by her sister, who worked for me.
Wife 3 was only marginally interested in flying, and in our short marriage, she only flew with me half a dozen times. Had we stayed married, I suspect we would have traveled by GA now and then, as she seemed to have no objection to doing so.
Now to current SO. She was really reluctant for me to buy my airplane, as her very limited experience in small airplanes was watching them with her Dad at the local airport where she grew up, and one very unpleasant flight in a SE charter from Denver to Fort Collins when she and her husband first came to Fort Collins when he was transferred here by the company he worked for. But when she saw how much I loved to fly, she agreed to ride with me occasionally. Our first flight was just before my airplane's engine cratered and I landed in a field, and that neither I nor the airplane were hurt was a positive. But subsequent flights weren't particularly interesting for her, and the coup de grace occurred on a flight to Nebraska, when to get into Holdrege, it was necessary to shoot an approach--and although it was a picture-perfect approach, that experience of going through a few thousand feet of clouds scared her so much that she wanted us to drive the rental car home instead of fly home. I persuaded her to fly home, but that was the last time she flew in my airplane.
So it's very hard to tell how your wife will be. She may find that she really enjoys it, or she may decide that you'll do all the aviating in the family. You can bend her toward flying by being very careful, taking no chances, and starting out on a nice smooth day, but obviously that's no guarantee. I wish you well.
Cary