Make sure she has her own pair of binoculars and point out various wildlife you see. Tell her to bring a book or something, but make sure she takes in the natural beauty of her surroundings.
My fiance is a vegetarian and generally loves animals more than people. I took her out and warned her that I'd shoot a buck if I saw one I liked, and that she had to be prepared for that. She was fine with it, but kept claiming "team deer." She watched several doe and yearlings, and a couple of very young bucks came out. When a larger, much more "shootable" buck came out, she pointed to him and told me it was okay to shoot that one. I passed (he was a little young), but she was sort of pushing me to shoot him. She had buck fever, and couldn't believe I let him walk!
Bottom line: it was a great experience for both of us, and she really appreciated seeing the process and watching all of the critters in the quiet of nature. I tell everyone they should take their significant other at least once.
