I'd say Hope is definitely petite for a RIR. But I think her being with out feathers and probably malnourished from "who knows when" might be whats got her looking small. It will be interesting to see how she sizes up after she feathers out and gets proper nutrition.
My hatchery RIR seems more petite than some of my other heavy birds, just in general, compared to orpingtons, rocks, etc...