Mary (Polly) Bonner, artist and printmaker, daughter of Dr. Samuel Lafayette and Carrie Ann (Hill) Bonner, was born at Bayou Bartholomew Plantation near Bastrop, Louisiana, on March 31, 1887. She and her older sister and brother, Emma Jane and William Feuilleteau, spent their formative years on the plantation. In 1897, six years after Samuel Bonner's death, the widow Bonner moved the family to San Antonio, Texas, in search of superior educational opportunities for the children. In 1901 Mary enrolled at San Antonio Academy, which was a coeducational school at the time, and after graduation she attended the University of Texas from 1904 to 1906. She also subsequently traveled in Europe and probably studied in Switzerland and Germany.
Her serious commitment to art began when she spent the summer of 1922 at the Woodstock art colony in upstate New York. There she decided to devote the rest of her life to the art of etching. Serious artists received scant encouragement in Texas at that time; indeed, the University of Texas had no art department until 1938. As Mary spoke French fluently, she chose to study in France; she set sail in the fall of 1922 and found lodging in a pension in Paris, where she lived part of every year for the next seven years. She searched among Parisian printmakers for a master from whom to learn the craft. She spent six weeks going from studio to studio before deciding that print maker Édouard Henri Léon offered the kind of instruction she sought. Léon was a product of the École des Beaux-Arts, the classical stronghold of French academic art, and from him she received superb technical instruction. As early as 1923, Mary Bonner began entering work in juried exhibitions such as the conservative Salon des Artistes Français favored by her master. Her etchings often received official recognition by this group: honorable mention, 1925, to Notre Dame, Paris; bronze medal, 1926, to Portrait of a Princess of the House of Este after Pisanello; silver medal, 1931, to Sunflower Girl.
Bonner asserted her independence, however, when in 1924 she exhibited three etchings in the Salon d'Automne, "where the most daring members of the avant-garde were welcome." Her entries, based on ranch life in Texas and titled Bucking Broncos, Cowboys, and Mesquites, attracted the notice of Parisian art critics. In the fall of 1925 she submitted another etching inspired by memories of South Texas. Les Cowboys, a three-part frieze, was one of the sensations of the salon and was reproduced by three French newspapers to illustrate their coverage of the exposition.
Édouard Léon and his wife journeyed to the United States early in 1927, accompanied by their hostess and guide, Mary Bonner. Léon served as a juror for the second Texas Wildflower Exhibition, held at the Witte Museum in San Antonio and sponsored by Edgar B. Davis. The artists did not let this duty infringe on their work schedule, however; Bonner and Léon spent most of their days painting and etching Spanish missions and other picturesque subjects in south central Texas.
By 1928 she had taken up the causes of art and conservation in San Antonio to the extent that she devoted less time to her own work. She was especially active in the San Antonio Art League, the San Antonio Conservation Society, and the Southern States Art League.
Mary Bonner spent the last years of her life quietly at the family residence in San Antonio. She was recovering from surgery when a blood clot caused her death on June 26, 1935, at the age of forty-eight. Funeral services were held at St. Mark's Episcopal Church, and her ashes were buried at Mission Burial Park.