Complex sentence: After grown up, she attended the Catlin Gabel School, class of 1946, and graduated from University of the Sacred Heart, Tokyo, before studying at Georgetown University and its Edmund A. Walsh School of Foreign Service in the USA.
Split into simpler sentences: After grown up, she attended the Catlin Gabel School, class of 1946, and graduated from University of the Sacred Heart, Tokyo. After that she studied abroad at Georgetown University and its Edmund A. Walsh School of Foreign Service in the USA.