i think it will be a great move to show their kids around and let them experience other lifestyle. besides, they will probably be much looking forward to some privacy.
i had a feeling they would choose the obama girls' school, although quaker religion is not popular in spain at all (although i have no idea if it interferes with catholicism). maybe they will choose a normal international school instead.
i thought georgetown was a nice choice, it's quite a quiet and nice area to live in, although perhaps a bit too young for them with so many students around?
I wouldn't call Georgetown a quiet area at all. It's a mix of students, shops, apartments, small (extremely expensive) houses, and large (astronomically expensive) houses. They'd have to have a huge house -- think $10 million and up -- to get something big enough for all their kids and have a little privacy.
There are other parts of Washington that are more exclusive and have bigger homes/more land, so those certainly would be a possibility.
Although a few of the single royals live in the city, others live in the suburbs. For instance, Reza Pahlavi and his family were in McLean, Virginia, for years. Farah Diba lived in Potomac, Maryland. King Hussein and Queen Noor had a house in Potomac, too, although I think she sold it a few years ago. CP Alexander of Yugo lived further out in Fairfax for a while, I think.
On schools, Washington International School might be a possibility for the kids, and it is near Georgetown, so maybe the rumors are right. Lycee Francais is in Chevy Chase, Maryland, which is a suburb just outside the city.
I seriously doubt, though, that they'd send their kids to Sidwell Friends, the school where the Obama girls (and Chelsea Clinton before them) went. First of all, it's extremely liberal, not just politically, but in the approach toward education/life. (Queen Sofia would have been expelled for politically incorrectness on her comments about "gay pride" a few months ago!)
Second, the lower school is in Bethesda, Maryland, not in Washington. Kids switch to the Washington campus in 6th or 7th grade, so they'd end up with the kids on different campuses anyway.
But, you never know. They'll probably ask their friends who live here what they think and where they send their kids to school, just like anyone else would.