I'm quite behind on my reading, (and writing I'm afraid), just having read part two. This is a very enjoyable adventure, the torment of giving a hint of what is to come next delicious torture to Cathy, but she can do little else but submit to the ladies plans for her anyway. It also makes sense that poor Cathy get some exercise, and what better way than running the snot out of her as a pony girl, with the added benefit of redirecting some of her erotic energy toward more useful pursuits.
I could see this adventure touching on all of the different interests here at the Plaza one chapter at a time, and possibly Cathy becoming a permanent member of Shackleton Grange after she has atoned for her sins. Could she even find a particular kink that interests her above all the others, after giving each a road test of course?
Thanks for sharing, Jackie.
PS. With all the forum updates there seems to be an information overload of sorts, at least for me, possibly explaining why some might not have commented on your excellent story.