Sometime during 1908, the Kers returned to New York and were divorced. In 1910, Mary Sigsbee attended Howard Pyle’s lectures. One of her fellow students was Anton Otto Fischer, the German-born marine illustrator and painter. They were married in 1912. During their married life, the Fischers divided their time between New York City and Bushnellsville, in the Catskills.
Between 1905 and 1917, Mary Ellen Sigsbee (sometimes using the Sigsbee Ker) worked fairly consistently as an illustrator. For ten years 1907-17) she wrote and did drawings for Arthur Brisbane, editor of the Evening Journal. Her work retained the Socialist leaning of her early student years.
Sigsbee worked again for a short time with Brisbane in 1930 as a writer and cartoonist. In 1940, the Fischers moved to Woodstock, New York, the artists’ community founded by a disciple of John Ruskin and William Morris, leaders of the Arts and Crafts movement. Sigsbee’s best known work, The Christmas Mouse, appeared on the cover of the Saturday Evening Posf for Christmas 1934. One of her favorite themes was children, particularly in narrative scenes with their mothers.