In Chapter 10 Miss Bingley continually asks Mr. Darcy to mention certain things for her in his letter to Georgiana. Is it reasonable to assume that she could have written to Georgiana herself? I know she's mainly looking for a reason to speak to Darcy and that's why she asks him to do it, but IMO she could have a better chance of getting closer to the brother by becoming more intimate with the sister. Am I missing some point of etiquette which would keep her from writing to Georgiana?