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 II, Scene 3

In Walpole's estimation, ". . . the expression of the passions [is] most masterly, particularly in the devotion of the countess with the porter."