I took an 8 year old boy on his first caving adventure on the Gypsum Passage expedition. I was a little concerned because caving can be dangerous, but our guide, Janie, was excellent. She was very attentive to his needs and paid close attention at the potentially scary parts. There were no problems.
The expedition itself was pretty low key. It's mostly flat with a large overhead ceiling. There isn't a lot of crawling nor is it very strenuous if you are reasonably fit. There are 3 potential difficult spots. The "birth canal" is about a 6 foot belly crawl that slants upward that might freak you out if you are claustrophobic. There is a ledge to cross coming in that has a steep fall that could get the best of your nerves. There is also a drop of about 12 feet that is a little technical, but if you take your time, you'll be fine. None of it is difficult with the right footwear, but fatigue or fear could get the best of you.
I didn't give it 5 stars because the equipment is old, worn, and not the highest quality, but it's good enough to get through. The scenery is lovely. You'll learn a lot and have a good time. It's definitely worth a look.