This is the exception, but wanted to relay a story that happened to one of my close friends - for the record, I am 33, female, married 10 years, and hubby does not play any online games. We have plenty of fun together when our hobbies are the same, but it's ok to have separate hobbies; in fact, it helps a relationship, if you treat each other, and each other's hobbies, with respect.
Anyway, some friends and I played EQ for about 3 years - None of our spouses played, and none of us had any issues with it. When DAoC came out, one of these friends talked his wife into playing. Since it was a fresh game, and he had no history or guild that she would have to contend with, she agreed - It went fine at first - she had fun, but over time my friend stopped being so excited about her being there all the time - He kinda let her go do her own thing, and stopped paying so much attention to her, so he could get back to his own play style - Well, she hooked up with a "saint, who is very patient with me, and helped me learn more than you ever did, and he's much nicer than you, and I feel like I'm in love with him, and you and I are getting a divorce." That's paraphrasing, but the outcome was the same. She left him and moved to another city, where this "saint" dumped her three weeks later. This all took about 4 weeks, from the time she started playing until she left him. She and my friend had been married for more than 11 years, but obviously had a weaker relationship than they thought.
What I'm saying is be careful what you wish for. If you're going to get her involved, you better be prepared to lavish more attention on her in game than some other guy will. There are plenty of guys out there who will pick up where you fall short, who will be patient where you can't, and who will tell her how much more he would appreciate her than you do, and none of them mean it. If she's the least bit gullible or emotionally immature, she might just fall for it.
I like to think that most women are not going to fall for this crap, but some do, and so do some guys. Just make sure it's really what you want, and if you decide it's not, play your games, support her hobbies, find some common hobbies, and let it be :) Good luck!