Who is Robin Gaddis from Heaven's Prisoners and what is their importance?

Robin Gaddis is a thirty-something alcoholic white woman who works as a stripper and prostitute in order to support her drug habit. She is very vulgar and usually speaks of herself in an abstracted third-person as 'mommy'. Robin is convinced that her best asset is her large bosom and when she is not displaying her breasts she is usually talking about them. Fairly intelligent and insightful, Robin does not consider herself as capable of much more than being an object of sexual desire.