We will be at Disneyland for two days in April - my husband has a conference and we are accompanying him. We have a 6 year old girl - so Ariel's Grotto and the Princess meal are a given - other ideas? We have no idea what to do or see.
My daughter is 4 and loves Ariels Grotto, all the Fantasyland Rides, Soarin, Haunted Mansion, PoTC, autopia, etc. Since its her first time, I would take time to see parades, to go to character meet and greets (Peter Pan by the Matterhorn, Mary Poppins on Main Street etc), she may enjoy the island as well.
Some of the height requirement rides like Space Mountain, Splash and Big Thunder will be up to her when she sees them. My daughter is pretty outgoing and one ride on Splash was enough for her for now.
Most of all, relax and enjoy. Seeing the sights will be amazing for her just don;t plan too much as it can get overwhelming.
Edit: I would skip the Princess Fantasy Faire if you can its fun but a lot of waiting. If you are doing the princess lunch anyway I would not do both that and the Fantasy Faire.
I just went with my son who is six. One thing I liked about getting into DCA by 10 am is that all the recent Pixar characters are out and about, with a few regulars, like Goofy and Mickey, too. We saw Mr. and Mrs. Incredible, Sully and a few others I can't remember... But he was really excited to see characters from Pixar movies he watches regularly. Also DCA is never crowded in the morning.....