@MissDaphne - That really was a good episode! A friend of mine who has oodles of money sends her daughter to the National Cathedral School in Washington, which is right near there.
It's actually an Episcopalian church. I think the term "catholic" in this context doesn't just mean Roman Catholic; Anglicans, Episcopalians, and perhaps the Orthodox churches also consider themselves Catholic churches. I guess it has to do with the structure of the church, etc.