you need to call. My son, his wife and three kids sailed with us on the Oasis. They had a cabin that appeared to be a modified Junior suite suitable for 5. It was a very large cabin, with a little room that had bunk beds- suitable for two kids. The true Jr. SUite has a walk in closet and these cabins have bunks in what appeared to be the walk in closet with a curtain.
The couch in the room was great for another child- These cabins are only available by calling the cruise line- of course, some two bedroom suites work, but are expensive. The 5 person modified jr. suite was cost effective.