Welcome to planDisney, Allyson!
I'm so glad that you stopped by with your question. Having taken a four-year-old princess to Walt Disney World, I think I'm in a good position to give you an answer.
In my opinion,
Magic Kingdom Park is the best theme park for young Mouseketeers. There are so many attractions that little ones can experience, such as Jungle Cruise, Peter Pan's Flight, Prince Charming Regal Carrousel, Dumbo the Flying Elephant, Mad Tea Party, and "it's a small world."
Magic Kingdom Park is also the best place for little girls to feel like true Disney Princesses. She'll be able to get a "practically perfect" photo in front of
Cinderella Castle. She can then stop by and say hello to
Princess Tiana and other visiting Disney Princesses at Princess Royal Hall. She'll love watching
Disney's Festival of Fantasy Parade, as the Disney Princesses promenade through the park on a sparkling castle float! She can then become part of Ariel's world by riding
Under the Sea ~ Journey of The Little Mermaid. If she wants the complete princess package, you might even want to consider the
Bibbidi Bobbidi Boutique experience.
Depending on how your princess is with loud noises, you can finish off the BEST. DAY. EVER. by watching
Disney Enchantment.
Having said that, each of the theme parks is enjoyable for kids. EPCOT has some great family-friendly attractions, like Remy's Ratatouille Adventure and Frozen Ever After. You can even
meet Anna and Elsa at their Royal Sommerhus.
Disney's Animal Kingdom Theme Park is wild and magical for kids. Kilimanjaro Safaris will bring out the Wilderness Explorer in anyone. I'm sure she'll adore the new shows,
Disney KiteTails and
Finding Nemo: The Big, Blue... and Beyond!Disney's Hollywood Studios is probably the least enjoyable park for four-year-olds. However, my daughter loved Slinky Dog Dash and Toy Story Mania. She even braved Star Wars: Rise of the Resistance and Millenium Falcon: Smuggler's Run! But she's a bit of a thrill-seeker!
I hope that's helpful, Allyson. I hope you have a magical trip.
Mike