if you do a search on working cockers, you should find some really interesting threads. somewhere there is a pic showing working cockers alongside show-types.
as i understand it, after comparing my working cocker with all the show cockers that we meet- workers
generally have slightly higher set, possibly shorter, ears (more like a springer spaniel), a smoother coat, and are built more athletically with longer bodies.
when barkley is next to a show type cocker, their heads are pretty much exactly the same shape but the difference in their ears is striking. also, barkley is nearly always bigger and faster. he is always mistaken for a springer spaniel (despite being almost entirely black) or a cross-breed. i have
never met anyone who has guessed that he is a cocker spaniel and most people look sceptical when i tell them that he actually is!
if you can post a recent pic of pringle, i'm sure people here will be able to tell you what they reckon. also, if you have her pedigree, and lots of ftchs (field trial champion) appear then there are definite working lines.