Yes, now you mention it I think there always is some slight difference betwwen Kitty and Lydia. :) Even minor gestures can signify true inner personality. She's so overshadowed by the wilful Lydia. I notice in Ch.7 when Lizzy goes to visit Jane, the sentence states '"We will go as far as Meryton with you", said Catherine and Lydia...' A rare time Kitty took the lead with a suggestion and Lydia just chimes in? Perhaps Kitty would secretly like to escape Lydia's dominance and emerge as a person in her own right in the Bennett family? But she doesn't know how to.