I think JA is mocking Laura's meanness. Laura claims all this sensibility, but is completely oblivious to how terrible she is and how terrible the characters she admires are. People are divided up into good people and terrible villains (because they're not sensible enough). I've read this attitude in some authors, though I can't think of any names of ones that JA might also have read). Laura is the one who casually glosses over stealing money and mothers starving to death.