Congratulations, Leslie!
First visits are always so fun and full of magical memories. Although many attractions do not have a height requirement, there are some attractions that do. I would hate for your Mouseketeers to be turned away from an experience because they do not meet the height requirement. Take a look at this Disney Parks Blog post that organizes all Walt Disney World Resort
theme park attractions by height requirement. These lists are by theme park and are very helpful when creating "must-do" experiences.
Here are a few experiences from my Mouseketeer's "must-do" list:
Magic Kingdom- Seven Drawfs Mine Train, Splash Mountain
EPCOT- Test Track
, Disney Phineas and Ferb: Agent P's World Showcase Adventure
Hollywood Studios- Toy Story Midway Mania, Star Tours: The Adventures Continue
Animal Kingdom- Kilimanjaro Safaris, Kali River Rapids
I hope this helps you plan your theme park "must-do" list for your first visit. Please let me know if I can answer other questions you may have as you continue to plan your family's first visit!
I hope you make many magical memories!
Missy