Hi Michelle,
What a wonderful surprise for your daughter! My husband and I have also surprised our children with trips to Walt Disney World and their reactions have been priceless. You should video your daughter's response when you tell her what the big surprise is. It will make a great memory!
My daughters are also tall for their age and I understand needing to have accurate sizing information. The princess dress sizes are the same in the Disney Parks as they are in the Disney Stores or DisneyStore.com. To find the nearest store near you, try the
Disney Store Locator. At a Disney Store you can try the different styles on and determine which size suits your princess the best. Typically I size up for my tall daughters when purchasing princess dresses from one of the Disney sources.
Michelle I have bought princess dresses for my daughters from the Disney Store, Walt Disney World and also from independent retailers. Both of my daughter's favorite dresses came from an independent retailer called Little Dress Up Shop. The dresses from this shop are all very soft, not scratchy, and have stretch velvet bodices which accommodate a variety of sizes and shapes. Their selection isn't as large as those available from the Disney Parks or the Disney Store, but they have replicas of the most popular Disney princess dresses available. One benefit of purchasing your princess dress ahead of time is that you know how the dress fits and if your daughter considers it comfortable to wear for long periods of time.
Thank you for your question and please let us know if we can help you any further with your Disney vacation planning. We are always happy to help!
Blessings,
Brenda ºOº