Whenever I cruised with my parents before I turned 18 my brother and I were always in a cabin next door or across the hall from my parents. The cabins are tiny so fitting 4 people in them is a tight fit, it made for a much nicer vacation. We didn't sail on Disney, but as long as you have an adult registered in the room you are fine. It's nice with a cruise since you can pick your specific cabins unlike a hotel and guarantee being near each other.