She at first was portrayed as haughty and arrogant, disliking her new life at the castle and thinking of herself as above the Player Characters who came to see her, as well as the other NPCs at the castle.
Over time, however, she changed her ways (having seemingly finally learned the Virtue of Humility), and attributed her earlier arrogance to anger at being dislocated from her original home to the castle, and apologized. She also became friends with Sherry the Mouse, whom she had previously scorned. (Sherry is, after all, still technically a rodent, though a much-beloved one.)
Following the Royal Council Massacre, Aileen and Sherry both disappeared. Sherry has since been seen, as of early 2009, but Aileen has not.