In addition to her writing, most recently appearing in her blog Art Vent,[1] she is best known for her paintings, which have often documented daily life in a manner described as diaristic, even compulsive, using dense, painterly, often indecipherable words, numbers and symbols in grid or geometric frameworks.
Born in Philadelphia and raised in Chicago, Diehl attended MacMurray College in Illinois for two years, after which she married a graduate student at Yale University (since divorced) and moved to New Haven, Connecticut.
"[9] Art in America critic Cary Levine described her work as possessing "the intimacy of a personal journal at the same time that it is made impenetrable by her abstract style and refusal to provide the key to her encrypted symbolism.
"[2] ARTnews critic Ingrid Periz wrote that the paintings' "disciplined surfaces make for lasting visual interest and … an almost meditative quality," in part due to Diehl's treatment of language as a formal device whose meaning cannot be decoded literally.
[10] In recent years, Diehl has moved from large-scale, complex, grids to more spare works of pencil and ink on paper that she describes as "merging precision with spontaneity.
Diehl was a Contributing Editor to Art in America (2007-2016), where she wrote cover articles on Olafur Eliasson, Robert Irwin, Wolfgang Laib and Christian Marclay, as well as numerous other features and reviews.