I too am blessed with a SWMBO that supports my habit. She likes it a lot better than my last "Hobby" (read addiction) Racing Nitro Powered Remote Control Cars, Buggies and Trucks. I am home a lot more, I spend less money, I don't come home grumpy, dirty and exhausted, and she sees how much I enjoy the fruits of my labours.
She bought my fist starter kit for me for Xmas, and then sort of panicked when the $120Kit RAPIDLY turned into 7 fermenters, 300 bottles, 12 kegs, 3 extra fridges, one less bathroom and now an outdoor brewing kitchen.
If I were dating a new woman and had this "hobby" I think I would introduce her to it by taking her out on a date to a Brew Pub and start talking about different styles of beers, the history of brewing, maybe compare fine beers of the world to fine wines of the world etc. Hopefully she would at least try a few types and like them, but if not at least she will understand your interest in fine brews. Then when you later tell her that you brew your own beer due to your interest in the craft and the fine beers of the world, she will understand.... and maybe even HELP on brewday!