40 inches is the biggest turning point in what rides will be open to a child. Here is a complete breakdown for you:
35 inches
38 inches
Kali River Rapids
40 inches
Dinosaur, Body Wars, Soarin', Test Track, Big Thunder Mountain Railroad, Splash Mountain, Stitch's Great Escape, Star Tours, Tower of Terror
44 inches
Expedition Everest, Mission: SPACE, Space Mountain
48 inches
Primeval Whirl, Rock N Roller Coaster
Additionally the Tomorrowland Speedway requires that drivers are 52 inches to ride alone. Anyone under that height must be accompanied by someone who is at least 52 inches.
Rides in the four theme parks that are not listed above are open to all heights. Really almost all rides are open to small people so your daughter will not be lacking in things to do, even if she doesn't meet the minimum height requirement for all the rides. I hope that helps your planning!