Just thinking "out loud" here...
How about starting with well-known Disney phrases - "When you wish upon a star..." "Third star on the left.." "It's a small world.." I think especially if you have everyone read their fortune one at a time, someone will add up that those are all Disney phrases. Then maybe move on to something like "Your Prince Charming will soon take you to his castle." Or "if the slipper fits, wear it." LOL
Maybe the second-to-last fortune could be "I see a trip to the happiest place on earth in your future" and the very last one could say "I see a trip to Disney World on (the date) in your future."
However you decide to do it, I know your family will be thrilled!