In 1776 Walpole wrote to his friend William Mason, "Lady Di Beauclerc has made seven large drawings in soot-water (her first attempt of the kind) for scenes of my Mysterious Mother. Oh! Such drawings! Guido's grace, Albano's children, Poussin's expression, Salvator's boldness in landscape and Andrea Sacchi's simplicity of composition might perhaps have equalled them had they wrought all together very fine."

Act V, Scene 6

Walpole notes "the resolution of the countess in the last scene, in which is a new stroke of double passion in Edmund, whose right hand is clenched and ready to strike with anger, the left hand relents."