She left her successful Michigan dental practice for a studio in Greenwich Village, New York City, and became a self-taught painter in the 1920s.

Her predictions of the future, her unusual artwork, her work with the poor in New York City's Bowery, and her late life marriage to Bush incited much interest in the national press.

She was widely appreciated "for her progressive and excellent work in the day when she fabricated inlays, crowns, bridgework, and dental plates in her own laboratory.

Brilliant color, power, and an unquestioned sense of design of a new and mystic school brought her work to the attention of art critics who reviewed her paintings with interest and favor.

"[1] Spore was "an early participant in an exploration of the field of extrasensory perception in collaboration with Dr. Walter Franklin Prince of the Boston Society for Psychical Research.

She felt that her painting was inspired and her art guided by artists long dead,"[1] perhaps originally introduced to her through the spirit of her deceased mother.

"[1] She received much publicity from both the mainstream press and sensationalist tabloids, which printed such articles as "Mystic voices led her to romance, fame and wealth"[5] and "Pictures my mother sends me from beyond the grave.

First with her own money and then with the financial assistance of other benefactors, she personally dispensed such things as meal tickets, clothing, spectacles, false teeth, and wheelchairs.

In 1942, Marian produced a series of small paintings of scenes from the island of Guam, where she stayed in the early 1920s while visiting her brother.

According to an art gallery newsletter, "these Guam paintings are delightful primitives, very colorful and full of the movement of the sea and palm trees.

"[9] As a wealthy Park Avenue resident, she operated a soup kitchen for the poor and needy in New York City's Bowery section, beginning in 1927.

Inside the headquarters, converted from a squalid tenement, she carried out the distribution of pants, overcoats, shoes, and other clothing, which Spore bought from stores which sold to her.

[12] Spore wrote a semi-autobiographical book about her spirit paintings, entitled They, which was published posthumously in 1947 by the Beechhurst Press of New York.

Her honesty and general character are beyond doubt...that she is able to state facts probably unknown to her to a degree beyond the limits of chance has been absolutely proved by me.