Hey there, Scannia! Welcome to
planDisney, and thanks a bunch for stopping by with your question!
I can completely understand why this feels confusing, especially because your child is already an
Annual Passholder. I actually looked into this to make sure I was giving you the most accurate information possible, and a very kind Cast Member helped clarify how these discounted
Water Park tickets work.
Unfortunately, the
discounted Water Park admission offered through Annual Passholder benefits can only be purchased by an adult Passholder. The reason for this is that Disney requires the Passholder purchasing tickets to present a valid adult photo ID, and purchases connected to those offers cannot be made under a child's name.
Because your child is the Passholder and not the adult in the party, the system won't allow those discounted guest Water Park tickets to be purchased. I know that probably feels frustrating, especially since you're traveling together, but it is tied specifically to the adult verification requirement attached to the benefit.
At this point, your options would be to either purchase regular-priced Water Park tickets for yourself or consider purchasing an Annual Pass in your own name if you feel you would use the benefits enough to make it worthwhile.
Scannia, I know this wasn't the answer you were hoping for, but I'm really glad you checked before arriving so there are no surprises at the ticket window. I hope you and your child still have the most amazing day splashing around at the water parks.
Warm hugs,
Ana Paula