Hello Cheryl!
I think you will win "Grandparents of the Year" if you take your granddaughters to Walt Disney World in June! I promise you will have an incredible time!
Walt Disney World is all about making MAGICAL memories for families with children. Many of the attractions are "practically perfect in every way" for your granddaughters, having no height restrictions at all. In fact, my two year old can ride many of these attractions!
However, on the more thrill-ride attractions, there are height restrictions. When you check out the
Attractions at Walt Disney World, you will see a "Height" tab on the left hand side of the webpage. Click that tab, and you will be able to find out what attractions are suitable for your whole family. There is not an age restriction on the Disney Park attractions; however, Walt Disney World does provide an appropriate age range for each attraction. You can also find this information on the Attractions at Walt Disney World webpage.
I hope this helps in your planning. If you have more questions, please let me know!
Have a MAGICAL day!
Wes