She had a lifelong relationship with fellow artist Maud Hunt Squire, with whom she lived in Paris and Provincetown, Massachusetts.

"[1] After the McClernand Grade School, Mars secured a scholarship and attended the Art Academy of Cincinnati beginning in 1892.

[4] Lewis Henry Meakin and Frank Duveneck provided instruction, which included drawing, illustration, and painting.

[5] Mars began working as a book illustrator in New York, as did Squire, after she completed her training in Cincinnati.

She continued to win prizes at the Illinois State Fairs during her trips home to visit her parents.

[2] Both Mars and Squire created illustrations for Children of Our Town by Carolyn Wells[6] and Adventures of Ulysses by Charles Lamb in 1902.

[1] Mars began wearing bright makeup, dying her hair red, and living a bohemian lifestyle.

A "seminal contribution to LGBT Lesbian literature", in 1922, Stein's poem was printed in Vanity Fair.

[1] Mars was an ambulance driver at the beginning of World War I, but the two women returned to the United States for their safety.