Eileen Monaghan Whitaker was born in Holyoke, MA. She studied art at the Massachusetts College of Art in Boston. For the next fifteen years, she worked as a commercial illustrator, producing watercolor sketches with fashion themes. She was a member of the National Academy of Design, American Watercolor Society, California Water Color Society, Philadelphia Water Color Club, and the Connecticut Watercolor Society. In the 1940s and 1950s, she earned a reputation as an important American watercolorist by having her work shown in major museum exhibitions. Since moving to California, she had continued showing on a national level, contributed to books on watercolor painting, and presented one-woman exhibitions in the San Diego area.