Hi Tracy! Welcome back to the Disney Parks Moms Panel!
It sounds like your children and their aunt and uncle are gearing up for a magical vacation! I can't think of anywhere I would like to spend a week more than the Walt Disney World Resort.
When it comes to
Annual Passes and the discounts that come with them, here is what I know. The Annual Pass and a government-issued photo ID must be presented by the Annual Passholder at the time of purchase. The discount is for personal-use only, meaning the Annual Passholder can only use the discount for their own purchases, not for other non-Annual Passholders in their party. In most cases, the dining discounts are good for the Annual Passholder and up to three Guests.
Any rules outside of those I listed are at the discretion of the Cast Member assisting you. While some things may still not be clear with these rules, my thought is that it never hurts to ask! I would suggest that your family plans on paying full price for their dining and shopping, asks the Cast Members if the discount with the kids' Annual Passes can be applied, then if the answer is, "No," they expected it, but if the answer is, "Yes," then they are pleasantly surprised!
I hope this helps a bit with planning the details of your kiddos upcoming trip. Please visit us again with any other questions you may have!
Tabitha