Create a new character and play along. Emphasize that this is a way for the two of you to spend quality time together. If you have two computers, create a new character for yourself and play along with your spouse. If you do not have two computers, you will want to purchase a second, or you may find yourself an observer of your favorite hobby. Remember to play nicely. This is new for your spouse, and if you have an arrogant attitude while playing this can stop your progress dead in its tracks. Have patience, make the play experience fun, and she will love playing with you. MMORPGs are a great way for couples to spend quality time together. They require teamwork, friendship, sociability, and take you to a far off land without leaving your home.
Introduce your spouse to a social circle. This could be a guild that you are in, or a group of friends that you normally play with. One of the biggest draws of an MMORPG is the community. Many gamers play just to interact in these social aspects of the game. If your spouse meets a group of people she enjoys chatting and playing with, this alone can be the hook. It will also allow you to have free time to play on your own, and allow her to gear her game play towards the style she enjoys the most.