Depending on the number of children on board, they do combine age groups for some activities. Although they both will have their own separate area of the Adventure Ocean facilities, they are in close proximity to each other. I know they do have activities such as special dinners with the youth staff, the talent show, and various other activities throughout the week in which age groups mingle with each other. You have chosen wisely because I believe that Royal Caribbean's youth program is one of the best at sea. I would suggest you sign each one of them up in their appropriate age group to start and see how it goes. Most kids enjoy the adventure.