A young artist working at the Shinnecock School run by William Merritt Chase, Marion Campbell met Charles Hawthorne, and they married in 1903. Their marriage allowed artistic freedom for both parties, and she became noted for her watercolor and gouache paintings that appeared transparent because of her skill in applying thin washes of color across the paper and of achieving great mastery over abstract space. Her work has been described as having "a freshness and beauty that is quite enchanting." It is likely that her work benefited from association with her husband who advocated canvases that "dripped with sunlight." In 1936, she compiled and published her husband's teaching notes titled Hawthorne on Painting.