Warfield's final book was published about a month before her death: The Cardinal's Daughter was a sequel to her novel Ferne Fleming, also published in 1877. In the book, set around the Civil War, the character of Jenny Crozier is dying, though resigned to accept her fate by a priest named Laurente, as her friend Ferne Fleming notices:
Death was very gently asserting his claims to one who had long dwelt beneath the shadow of his sweeping garments, and been taught early to recognize him at a distance as her friend and benefactor through the household presence of religious fervor...
She was resigned now to the inevitable... she was no longer afraid of death, which is a great gain to the dying. As a wise parent takes the hand of a timid child, and lays it gently on the neck of the watch-dog, chained in his kennel, to make him acquainted with the household guardian and dispel the terrors of his nightly prowl beneath his nursery windows, so had Father Laurente familiarized his dying charge with the grim features and repulsive exterior of the universal benefactor.
There is an elation in the sensations of those about to shake off this mortal coil, that very often simulates inspiration in its daring flights of imagination, and, it may be, clairvoyant knowledge of the future condition of the struggling soul.