How would you perform the role of Nora (when Kristine first enters) in order to show the thoughtful nature of this character for the audience?

Nora’s skewed vision of the world is most evident in her interactions with Mrs. Linde. Whereas her old school friend is wizened and somber, Nora is impetuous. Her choice to tell Mrs. Linde about her secret seems to be more the boast of a child than the actions of a thoughtful adult, and Mrs. Linde also refers to her as a child. So how would I perform Nora? I'm not an actor but if the play were being followed I'd perform Nora just the way she is supposed to be. Nora certainly looks and sounds childish and naive.