Hi there, Catherine!
I just love that you're planning so far ahead for your next trip to the Walt Disney World Resort! I can't think of a better place to celebrate your daughter's graduation either. What a special treat that's going to be for the entire family! Be sure to notate your
celebration when you make your reservations!
When you book your vacation, you will be asked for your child's age at the time of travel, so you'll want to put 18. The Park ticket and Dining Plan pricing is the same for everyone ages ten and up, so there won't be a difference in her price.
As far as
vacation insurance, if you want to purchase it for this trip, you must purchase it for everyone in the party. I've included the link above that will take you to more information and details about what the insurance will cover.
I hope this helps! Please come back and see us again if we can be of any assistance while you're planning your magical vacation!
Have a Pixie Dusted trip!
~Jackie