"Ah, poor Jenny's case" ...
This is an allusion to Dante Gabriel Rossetti’s poem “Jenny” about a sleeping prostitute. That poem refers to “poor Jenny” and begins with an epigraph from Shakespeare’s The Merry Wives of Windsor:
“Vengeance of Jenny’s case! Fie on her! Never name her, child!”—Mrs. Quickly"
(which leaves off the last bit, “if she be a whore.”)
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