Question: Which courtier did Empress Elisabeth of Austria suspect of being a spy, in part because she was a confident to the identical twin sister of Princess Maria Anna of Bavaria?
Sentence (from "Mary Drake"): "Pretty Little Liars" is a television adaptation of the novel series of the same name written by Sara Shepard, in which the antagonist Alison DiLaurentis has an identical twin sister, Courtney DiLaurentis.
Relevant evidence: No