Hi Anthony!
I love that you're trying to surprise your wife! You can visit Disney's Floral & Gifts website at
www.disneyflorist.com. You can choose from so many items to surprise your wife in celebration of your anniversary. Have flowers and chocolate delivered or go really nuts and do the "Presenting Your Royal Princess" package. Your wife will return to her room to find that Fairy Godmother has visited and left her all the things including a royal proclamation that she'll need to be a princess! I've seen the gifts personally (tiara, wand, swarovski crystal jewelry) and it's all beautiful.
Go to the Romance/Anniversary tab on the left hand side of your screen to find all of the wonderful in room celebrations offered.
Another thing you can do is order a cake to be delivered to the table after one of your meals as a surprise. It can be personalized and decorated how you want it. Feel free to add her favorite Disney characters. For special custom cakes you can call the Disney cake line at 407-827-2253. They will guide you through choices, give you ideas and, of course, answer your pricing questions.
I hope these ideas help! Congratulations and best wishes for a great trip, and of course, a magical life together!