<p>
But the basement doesn’t <em>belong</em> to S1. Presumably as S2 gets older he will also have friends over and want to use it.
S1 can go to the attic and D can have S1’s room. The daughter will get over not being a princess anymore. Way too much thought is being put into the “feelings” of these kids. Parents should do what is reasonable and practical for those who live there the majority of the time.</p>