Tara - My teen son and his girlfriend recently went on the waterfall tour. This should only be done by physically fit people.
His girlfriend had a hard time climbing the rocks, even though she appears fit. My son, who works out, climbed higher than she did, but said it took all the strength he had in climbing with the ropes. So maybe just your kids could go on that tour - unless you and your husband are Mr. & Mrs. Jack LaLane.
The tour lasted all day, which included breakfast and lunch. They were back by 5. They thought it was a wonderful experience.
I believe there are several tour operators that do the waterfall tour and each may have different programs (easy to extreme).