A Chicago native, Margaret Johnson attended high school and art school as a classmate of Walt Disney. He went on to make the most famous mouse in history; she married Myron Brundage, an alcoholic (and former hobo), and sold magazine cover art for $90 a piece in order to take care of her family. She did divorce the husband, but spent the rest of her life in relative poverty.
She did have a heyday, though. From 1933-1938, she was a highly popular cover artist for two publications: Weird Tales, home to H.P. Lovecraft and Seabury Quinn, and Oriental Stories (later changed to The Magic Carpet). She also did fashion illustration work, although it is difficult to find.
Brundage created 66 covers for Weird Tales during her time with the magazine. From 1933-1936, she did 39 consecutive issues. Her specialty was beautiful women, usually mostly naked, in some sort of dangerous situation--surrounded by cobras, being whipped by a masked man, being stalked by the devil.
This art was dangerous, erotic, and highly popular, so much so that some of the magazine's contributing authors began writing certain scenes into their stories because they would make great Margaret Brundage cover art. There was some controversy eventually, because the women of Chicago and surrounding areas objected to such chauvinistic (and a little bit S&M) subject matter. But, as soon as the editor revealed that the artist behind these dramatic scenes was a woman, everybody was okay with it.
Then, the worst happened: Chicago tried to get morals. The mayor put certain "decency standards" into place, which meant that nude pulp fiction covers were no longer appropriate for newsstands and bookstores.
Weird Tales relocated to New York City (just try to clean up those morals!), and Brundage was unable to move with them. Since she worked solely with pastels on illustration board, which couldn't survive being shipped from Chicago to New York, she and the magazine had to part ways. They found local New York illustrators, and she was pretty much out of a job. She did sporadic freelance work, and a few sci-fi conventions and art shows (where several of her originals were stolen), but in the world of illustration, she was expendable.