I don't have experience with this (yet!!!) but I would want the 4th bedroom for daughter. It is ***SO*** common for children to return home for extended periods of time, I think it would be less stressful all around to have a room available. It doesn't have to be a large room, but some privacy and separation are important for people to get along in close quarters. Later on (hopefully *much* later on!) it can serve as a room for live-in help or visiting grandkids.