Hi, Briseida!
I honestly cannot think of a more magical place to celebrate a Quinceañera than at Magic Kingdom Park! It's definitely fit for a Princess! In fact, lots of Princesses of all ages wear their gowns to walk around the Park. You may just want to have your daughter bring a change of clothes so she'll be comfortable walking around the rest of the day.
Guests are always welcome to pose for pictures in front of Cinderella Castle! You can have one [or many] photos taken by the Disney PhotoPass photographers and you can take them yourselves as well. There are so many places where she'll be able to pose and you'll be able to see the Castle in the background. A couple of my favorite places include a little path located just off the bridge on the way to Tomorrowland and another that's right in between Crystal Palace and the red and white tables in front of Casey's Corner. It's fun to capture the magic from different angles!
If you'd prefer to have a private portrait session where professional pictures could be taken of your daughter, you can schedule a private session with
Disney Fine Art Photography and Video. They can be reached at 407.934.4004 and they'll be able to plan the most magical photo session you could ever imagine! I've seen some of the gorgeous photos from these sessions and they're really a treasure. You have lots of locations to choose from too!
I really hope this helps with your planning, Briseida! Thanks for stopping by the Moms Panel and please let us know if we can help with any other questions you have!
Wishing you and your family a Pixie Dusted vacation!
~Jackie