Secondary characters have imporant functions in novels. What is the function of Georgiana Darcy?

Georgiana can be mistakes for being too "proud" but Elizabeth figures out pretty quickly that she is merely shy. Georgiana brings out the social pressures a young woman of nobility was subject to. The fact that Wickham was able to convince her that he was dashing brings out the fact that Wichham is a slimy guy and Georgiana is shy and impressionable.