9 or 10 is quite a bit different than taking toddlers along.
IMO.
As long as the parents are trained experienced sailors and have the proper gear like the family in the article the kids age wouldn't matter. Illness can strike anyone an time at sea. The risk for anyone is 8aually dehydration. Om smaller Navy ships sailors get Medevac'd off either to a carrier with a surgeon or to land. The parents if the article was right were trained by a high ranking Coast Guard friend who also said they and the boat ere capable. The illness the kid developed sound like it could have been contacted when being treated earlier for food poisoning.
By the logic being used people who live on the Bayou etc should move away till their kids are older. Believe it or not many land venues hold much higher risk for kids than that boat even at sea.