I think I agree that it's a partridge rock. It's tail is a little blunt, but it's comb is awfully small and it's legs are kinda thin. The other rock cockerels are bigger, with thicker legs and stand up taller.
Ooh how they change! Toss-up now...leaning toward pullet. But then I'm a newbie too
My males aren't quite that old yet but don't have that much tail, whereas the girls do. Plus, it's just standing "forward" not upright, but that could be just luck of the snapshot too. How does it compare to your female rocks?
The tails, combs, leg diameter and stance are similar to my rock pullets. My other, more gender-definite, rock cockerels have bigger, red combs. This runty thing's comb is pale yellow.