Weve taken our son at 11 mos, 23 mos, and just recently at 35 mos. Each time we have tipped the room attendant, waiter and assistant waiter 100% from him. The room attendants have always been great about emptying the trash more frequently, supplying bags for the nasty diapers, exchanging lifejackets for the right size, removing the items in the fridge so he doesnt eat them (and we get charged), etc. The waiters usually went out of their way to bring my son's food out at just the right times, and often entertained him with origami, napkin folding, peek a boo, etc. As long as they do something for the child, then you should tip something. If they go out of their way, then tip 100%!