Marguerite Zorach was one of the few really prolific female post office muralists (at least by www standards). The Zorach Collection, the estate of Marguerite and her husband, exists to this day. In addition to painting, Marguerite was a textile artist and graphic designer. You can see some of her work at the Smithsonian American Art Museum website.
Marguerite painted three post office murals: Haymaking (Monticello, Indiana), New Hampshire Post in Winter (Peterborough, New Hampshire), and Autumn (Ripley, Tennessee).