Merlot is one of Despereaux’s older sisters. When Despereaux is little, she attempts to teach him how to nibble paper in the library. But like Lester and Furlough, Merlot believes that mice should act in very specific ways—so she’s aghast when Despereaux seems to be speaking to the paper and refuses to eat it (unlike most mice, Despereaux can read the story in the book he’s supposed to be eating). This leads her to believe that Despereaux is mentally unwell.