Orphaned at nine, Mary Elvinger moved to Montreal to live with relatives and began working as a secretary for the Luxembourg government in exile. It was during this time she met her future husband, diplomat Pierre Elvinger. Following the liberation of Luxembourg in September 1944, Mary continued her work for the Ministry of Foreign Affairs before returning to Luxembourg in 1945. She was a key figure in founding the American Women's Club of Luxembourg. After Pierre's death in 1967, Mary joined the teaching staff in Formosa (now Taiwan) and later taught French at the newly established American School in Luxembourg.

In her memoir, A Gleam in My Eye, Mary Elvinger shares letters written to friends in Canada and the United States between 1944 and 1946. Through these letters, she recounts her arrival in Europe, her impressions of the journey, her love story, and her experiences of acculturation in Luxembourg, highlighting cultural differences and her life after her husband's death.