Does she like cooking? That's the analog I've used. My wife isn't involved, but she will drink the odd beer here and there, and she's been supportive.
I'm not sure having her involved would help much; having an extra set of hands would be less work for me, but I don't think I'd save much time. On the other hand, it would be nice to do it together.
I think part of what has made her supportive is that I handle all the cleanup involved w/ brewing. Other than small bits that go in the dishwasher, she doesn't touch any of the equipment for cleaning. Not that she can't, it just was my sense that if I was going to pursue this then whatever negatives were involved would be my responsibility.
I'm a little surprised she hasn't shown more interest just from a curiosity point of view. She likes to cook, to try new recipes, and certainly likes to explore things in cooking. But not so much interest in brewing.
[Funny story: I brewed an ESB with some new elements of the recipe and as of a week ago, I was very disappointed in it. Well. Saturday I tried it again after another week conditioning and Wowzer! It went from a beer that did nothing well to....a beer of which I had several refills. Her comment: "You've sure learned a lot about brewing, but the one thing you still haven't learned is patience."]