Hey there, Hi there, Ho there, Mohamed!
You're as welcome as can be here at the Disney Parks Moms Panel so thanks for your great question. Your daughter is going to have SUCH a magical and memorable trip to the Happiest Place on Earth!
Theme park tickets are required for both Disneyland Park and Disney California Adventure Park for all Guests ages three and older. This means your little princess
will require a park ticket. Luckily children ages 3-9 can enter with a child ticket that is less expensive than an adult ticket which is for Guests ten years of age and older.
There are countless experiences for kids of this age. When my son was three he really enjoyed meeting his favorite Characters, seeing live entertainment around the parks, and interacting at shows like the Disney Junior Dance Party! When it comes to
attractions, three year olds can still ride MANY attractions in both parks. Keep in mind that most attractions do not have a height requirement meaning they are safe for even the littlest of Guests. My son at this age loved (and still loves) Peter Pan's Flight, "it's a small world," Dumbo the Flying Elephant, and Toy Story Midway Mania to name just a few. With some other attractions in the 32" to 40" height requirements, your daughter may get to ride even more.
I hope this helps, and please return if you have any other questions while planning your Fantasmic trip!
-Jennifer