I think you need to do a benefit to risk analysis.
1. what are your requirements in a future wife? Good looking, home body, dotes on you, 100% loyal, good partner, kids, work/salary management,dance partner, camping, etc.
2. If she selects you for a husband, how does she stack up against your requirements?
If the answer is that she fits your requirements, then I would continue to see if I could steer the relationship in my direction with a 2 year window. At the end of 2 years, I would cut the cord and look for other candidates.
Also, what are the benefits you are getting today in the relationship, are they worth another 2 years of uncertainty?
Sometimes being 2nd best and getting the prize is well worth while.