In this almost full-length portrait, the imposing figure of Miriam Kilby (1696–1765), wife of the Boston merchant Samuel Hill, dominates most of the canvas. The very sober setting is based on a few elements such as the simple red curtain in the background and the books on the table by which she poses. The brilliant white of her muslin headdress, the scarf on her shoulders and the frills on her sleeves is set off by the predominantly reddish and brownish tones of the composition. Unlike other portraits by Copley in which the sitter usually holds some object, Mrs Hill’s hands are clasped together and rest placidly on her lap, affording her pose greater dignity and indicating her austere, calm nature.
It was in this period that Copley began to portray mature women with penetrating gazes that reveal their personality. Miriam Kilby, who was approaching seventy at the time her portrait was painted, conveys an impression of strength and authority. As John I.H. Baur pointed out, her features suggest “a sceptical, worldly personality modified, one would say, by a certain humor, or at least tolerance.”