but I am the mother of twins!
I really would recommend that you either go before your wife hits 20 weeks, or after the twins are born (6 months -12 months is a GREAT time to take babies to Disney)
Here's why I recommend this:
1. I
really started to slow down after 20 weeks. Most moms of twins will tell you that your wife's belly will really explode at this point. By 24 weeks, even a short trip through Target was tough for me.
2. September is HOT in central Florida. I would really worry about dehydration. Dehydration can lead to premature labor. Do you really want to spend time in the ER while your wife has to rehydrate and have labor halted?
3. My OB told me to have everything done that I'd like to personally do before 28 weeks, as she said that twin moms tend to be put on bedrest at that time. Sure enough, I was on bedrest at 27w5d for the remainder of my twin pg.
I really think going at this point in a twin pg is a bad idea. Too much can happen between now and then, and the stress on her body from touring the parks may be too much for the babies. I'd definately try to move up your dates or wait until your twins are born and on a schedule. We took our twins at 6 months and it was the easiest trip we ever had with them.
Best of luck to you with the pregnancy, delivery and twinfantdom. Having twins has been the most amazing experience I have ever had (it's better than anything in Disney, but shhh ... don't tell everyone around here that little secret

)
Noelle