You will have so much fun. Anything without a height requirement is fair game.
My youngest daughter was about that age for her first trip and she had so much fun on everything. Like CalGal, she didn't know better to be afraid of dark rides and loved just about everything. Pirates was one of her favorites. She did get a bit scared on Pinocchio, but I think that was more the jerkness of the ride, but the Whale at the end is a bit frightening.
Start off slowly, with bright outside rides. Fantasyland in the morning is always good. Ride dumbo, teacups, carrousel, story book canal boats, then maybe small world for a bright cheery inside ride, Jungle book, I haven't ridden it yet, but Pooh should be a bright cheery ride also. If those seem to go well, move on to the dark rides.
I know you didn't ask, but my biggest piece of advise is to be at the gates at opening time, actually we get there 30 minutes before, and head straight to Fantasyland. It is usually very slow in the mornings, Saturday morning is my favorite day there. You can do most of those rides in the first hour and if you want, head to toontown afterwards. Somedays Toontown opens later than the rest of the park and you can be one of the first in there also. If you have a few adults in your party that want to go collect the fast passes, have them meet you in fantasyland. They can collect a fast pass and ride the big rides, then meet up with you. the Fast passes can be used later in the day when the crowds get there. Even if it's past the time on the fastpass, the CM will still take them. They just have to be for the same day.
More than you asked for, but I hope you have a wonderful trip and take more film than you think you need. It is expensive in the park.