Margaretha Tchen-Vredenburg, 99, of Concord died Tuesday February 5, 2013 in Boston. Born in Utrecht, Netherlands on June 6, 1913, she was the daughter of the late Jan W. and Marie-Jeanne (Roos) Vredenburg. She attended schools in the Netherlands, and was a 1935 graduate of Deaconess Hospital School of Nursing in Den Haag, Netherlands, where she also was employed for several years. She spent the war (WW2) years in the Netherlands taking care of her parents and brother. She came to Washington, D.C. in 1948 and worked as an R.N. at Doctors' Hospital. Mrs. Tchen-Vredenburg was a longtime member of the American Youth Hostels, Theosophical Society and Society of Friends (Quakers), all in Washington, D.C. A Concord resident since 1996, she is survived by three sons, Sumin Tchen of Concord, Yumin Tchen of NYC and Weimin Tchen of Melrose. Also survived by their spouses Jane Young and Pauline Gobeil and three grandchildren, Michael, Julia and Daniel. She was the sister of the late Annie, Johanna, Susanna, Marie and Hermann Vredenburg, all of the Netherlands. Service: Services will be private.