Well another good web site to look at is US News & World Reports.
http://colleges.usnews.rankingsandreviews.com/best-colleges Just keep in mind that their "ratings" are only one such metric don't get too hung on up on their rating numbers. But their web-site has a lot of good information side by side.
I don't personally know too much about the universities in D.C. Will you be looking just outside in the beltway as well? The only D.C. schools I know students who attended are American University, and Georgetown.
As for U.S. private schools your daughter will want not only grades from her school & SAT or ACT's, but a list of extra-curriculars, a teacher recommendation, and she will need to write a personal essay. My experience is 'test optional' schools in the U.S. required a writing portfolio instead of the SAT's. So at least for my son the SAT's are preferable.
Is cost an issue? Will you be able to play for the cost of a private elite university?