Yes, Wesley, it's sad when a word gets corrupted or usurped to the point where you kind of have to stop using it if you want most of your audience to understand it, but that does happen.   It's hard to use "gay" to mean "happy" in your lyrics any more if you don't want to be misunderstood or hear snickers from some in the audience -- a real pity, since it rhymes with so many other words.    I'd love to rescue the word "parameter," but it's too late.) You get called on the carpet if you use the word "nigardly" nowadays, too.   ( Far too many people don't know what it means and that it's nothing to do with race or skin color or even being an outcast.   

"Picaninny" sounds to me like an obvious derivative of "piccolo" (Italian) or the Portugese "pequenino."   

If you don't like "cotton pickers" and you want to keep the image of little ones (white or black) slaving in the fields, how about "pickin' kiddies" or "kiddie pickers?" Or even "little pickers?"    Personally, I prefer "cotton pickers," but just sayin' ...