When my husband and i started dating we slept together in a twin. Now we sleep in a king with 2-3 cats, and a dog if there's a storm. Sometimes on vacation we have a room with a queen. Makes you realize how much space the animals take.
A queen sized bed is only big enough for one 5 year old. Trying to get more people in there results in sleeping on the couch so you don't punch your child.