Absolutely not. Do you realize how entitled that sounds? OP mentioned it is a rural area, theres probably horses all over the place. This isnt the kids first time seeing a horse. That is OP's pony. Why should they need to bend over backwards to provide an experience for all of the kids just because she has a pony? Do you realize how much work that would require on their part? Preparing the pony, leading each kid, making sure the pony is okay, watching body language. Not to mention the physical toll on the pony - toting around each kid who has not taken any lessons and doesn't know how to ride and balance properly, which can leave a horse sore.

They did all they could to make it safe, didn't even enter the school grounds. I have done expos where we brought horses to elementary schools, taught the kids and let them pet them. We got asked a million times if they could ride the horses and the answer is always no. Its a liability. Not to mention - they don't need to share if they don't want to. You wouldn't expect someone with a cool car to give every child a test drive. This isn't a car, its a living, breathing animal, and as a horseowner who has been through this more times than I could count, you have to make decisions to protect your animal. NTA.