By cartoons do you mean the classic animated movies? I definitely recommend having her watch all of the princess, fairytales, and Pixar movies.
How old is DD? If she's old enough to ride Tower of Terror, they have a Tower of Terror movie - it's cute. There's also the Haunted Mansion and Pirates of the Caribbean movies. Then High School Musical is big at DHS.
Maybe an Indiana Jones movie. Then the Wizard of Oz (great movie ride).
As long as you have the classics down (Cinderella, Beauty and the Beast, The Little Mermaid, Snow White, Sleeping Beauty, Pinnochio, Dumbo), then some of the more recent but old for the new generation (Pocahontas, Mulan, Tarzan, Hercules, Toy Story, Monsters Inc, A Bug's Life), you should be good.
Hope she has a great time at WDW!