Towards the end of her life, particularly after the death of her husband, Wilcox had become particularly interested in spiritualism and communicating with her dead husband. Throughout her life, however, she wrote poems which frequently delved into questions of death. This one, "Sleep and Death," was published in 1900:
When Sleep drops down beside my Love and me,
Although she wears the countenance of a friend,
A jealous foe we prove her in the end.
In separate barques far out on dreamland's sea,
She lures our wedded souls. Wild winds blow free,
And drift us wide apart by tides that tend
Tow'rd unknown worlds. Not once our strange ways blend
Through the long night, while Sleep looks on in glee.
O Death! be kinder than thy sister seems,
When at thy call we journey forth some day,
Through that mysterious and unatlased strait,
To lands more distant than the land of dreams;
Close, close together let our spirits stay,
Or else, with one swift stroke annihilate!