Make sure if you get her involved in FF somehow, that you do it on seperate accounts. Sharing an account on FFXI was the beginning of the end of my wife and I's relationship.
This opened up a whole new can of worms that we never realized before how much we were incompatable, after 7 years of dating, 3 years of marriage and 3 children. We've now been seperated for the past 2.5 years, with divorce papers finally in the works.
I still refuse to believe FFXI is the single base problem that caused our demise. However, I do believe it opened our eyes to other serious problems in our relationship.
So good luck to you in whatever you choose to do. Just believe that FF can, and will be a gateway to the end of relationships, if you let it.