To "meself" (eek, I'm talking to meself!): Please allow me to say once again that although the most common usage of "pickaninny/picaninny/piccaninny/(similar spellings)" was in reference to small black children, the word was also used in reference to older children and teenagers, and even adults (probably young adults) of limited mental faculties such as the Prissy character in GWTW. I agree that the latter is an "odd instance" in that it is less usual than the word's use as a reference to a child, but I disagree that it's an "academic manipulation" by the writer of that article; the character Prissy is called "dat lil pickaninny" in Chapter 8 of GWTW by another slave (Peter), and then she is described in the following paragraph:

Scarlett looked at Prissy and sighed. Prissy was not the most adequate of nurses. Her recent graduation from a skinny pickaninny with brief skirts and stiffly wrapped braids into the dignity of a calico dress and starched white turban was an intoxicating affair. She would never have arrived at this eminence so early in life had not the exigencies of war and the demands of teh commissary department on Tara made it impossible for Ellen [Scarlett's mother] to spare [other slaves to serve as nurse for Scarlett's baby]."

So, in the book Prissy is described as "pickaninny" AND recently assigned an adult duty. Her age is ambiguous in the book, but in chapter 19 Scarlett plans to send her away from Atlanta to Tara with Scarlett's baby, a journey and a responsibility she would not have had a child take on. Yet, of course, Prissy does not prove to be a very responsible adult!