Lots of pictures at link below. Pretty interesting.
http://bjws.blogspot.com/2015/09/labor-day-women-children-in-workplace.html
"A little spinner in a Georgia cotton mill. January 1909."
"Laura Petty, a 6 year old berry picker on Jenkins Farm. "I'm just beginnin'. Licked two boxes yesterday." Gets 2 [cents] a box. Rock Creek, Md, June 1909"
"At the Maggioni Canning Company in Port Royal, South Carolina, children shucked oysters for 4 hours before a half day of school, returning for 3 more hours of work after school."