Complex sentence: She initially went to public school, but in ninth grade she was disciplined for protesting the Vietnam War by wearing a black armband and she was moved to the progressive St. Stephen's Episcopal School for high school.
Split into simpler sentences: She initially went to public school, but in ninth grade she was disciplined for protesting the Vietnam War after she wore a black armband. She then attended the progressive St. Stephen's Episcopal School for the remainder of high school.