I'd tell that it may be too much for her to go when she has so much going on right now. Just be honest too, that with both of you being pregnant it kind of defeats the purpose of her coming along to help you out, and with it being her first pregnancy, she may not know how great she's going to be feeling especially at WDW. At least you have the benefit of knowing what pregnancy is like for you , but that the 1st time you're usually more tired, not sure how your body's going to handle it, etc.