Sonja Edith-Marie (Lennhart) Marshalek, passed away January 12, 2020, after an almost six month battle with cancer. She was 80 years old. Sonja was born in Copenhagen, Denmark on March 1, 1939 to Ossian and Edith (Folke) Lennhart.Sonja is survived by her two loving sons, Thomas and Frank; three nieces, in Denmark, Vibeke, Agnethe, and Lisbeth, and their children and grandchildren.Sonja was preceded in death by her parents, her husband, Eugene, and her two older brothers, Tore, a doctor, and Erik, an engineer.As a small child in the 1940's, Sonja witnessed the German occupation of Denmark. As a young adult in the Copenhagen area, she attended finishing school, worked in a bakery, and began library school.She met Eugene Marshalek, her husband of 47 years, at a mixer in Copenhagen, where he was doing his postdoctorate work in physics at the Niels Bohr Institute. They were married December 8, 1962. Their first child, Tom, soon followed, and the couple moved to Mastic Beach on Long Island, New York. In 1965, Eugene's new job as a Professor of Physics at the University of Notre Dame brought the little family to South Bend, Indiana. Their second baby, Frank, was born there the next year.After raising her two boys, Sonja returned to her education, earning Master's degrees in German at Notre Dame and in Library Science at Indiana University. She went on to work in libraries at IU South Bend and St. Mary's University.Sonja cherished family dogs throughout her life, and was a supporter of Pet Refuge locally, as well as numerous other national charities, especially those that champion the welfare of animals. After retiring, she enjoyed hobbies such as scrapbooking and assembling large jigsaw puzzles, which she would preserve in frames. She often shared these hobbies and other good times with her beloved friend and neighbor, Bonnie Ramsey.Tom and Frank are planning Memorial gatherings for their mother in South Bend and Bloomington, to be announced at a later date.Contributions in Sonja's honor may be made to World Wildlife Fund, 1250 Twenty-Fourth St., N.W. P.O. Box 97180 Washington, DC 20090-7180, or Pet Refuge, 4626 S. Burnett Dr. South Bend, IN 46614.