First question: Boy, girl or both?
Second question: Where are you? Don't need an exact location, but are you in Philadelphia, on the Main Line, etc.?
Third question: How old are the children? (Masterman is middle and high school, while many private schools start in Pre-K/K.)
One of my parents attended GFS for middle school, though it was a long time ago. From my folks to my kids, my family has had students in GFS, Baldwin, Springside (now combined with Chestnut Hill), Haverford School, Friends Central and French International. We know students who have attended many Philadelphia area private schools, as well as some who went to Masterman.
For the most part, I have found that area private schools, as well as the good public schools, may not cater to gifted kids, but there are a good number of gifted students in these schools. Kids will find gifted peers, and high school classes for honors/AP kids are often seminar/discussion style classes, which seem well suited to gifted kids.
Also let us know if there are extra curricular activities that your children want. My two older ones played a sport at a fairly competitive level (travel for a number of years), so there may be other factors to consider.
