aprilgail2 is correct. All of the cabins below category 4's hold only 3 - 4 people regardless of age. So, they would have to get a catagory 4 or two lower category cabins. The lowest category to connect would be category 10's, and the first two people in a cabin is charged the adult regardless of age. So, if they decided to book the category 10's, they'd be charged 4 adult fares and one infant fare.