Hi Melissa,
Thank you so much for visiting the Disney Parks Moms Panel with your question. We love helping guests to plan magical vacations! I think that you will find a lot for your girls to enjoy at each Disney theme park, and which you choose for them will depend on their personalities and interests.
If your daughters love animals, you must go to Disney's Animal Kingdom. From a ride on Kilimanjaro Safaris to see animals such as elephants and giraffes, to heading to Affection Section to pet animals, this theme park is a must for animal lovers. Disney's Hollywood Studios is the place to be if your girls enjoy Disney Junior or Star Wars, as you will find attractions and experiences featuring each of these. My daughter is 10 years old, and from the time she was born, Epcot has been her favorite theme park. She enjoys the variety of attractions, from Spaceship Earth to Journey into Imagination with Figment, and also now enjoys walking around World Showcase and sampling food from the different nations.
In order to get some further information about which theme park your girls might enjoy the most, I suggest that you watch the free
Walt Disney World planning video. You can watch this with your girls and see which theme park they respond to the most.
I hope that these thoughts are helpful for you, Melissa. Have a wonderful time planning your magical vacation, and please do let us know if you have any further questions.