Now a few things have changed, I am heavier now, almost back to my highest weight again, but trying to fight my way back down. We have been riding in a training martingale. Other than those 2 things, everything else is the same. It has been our longest, uninterrupted period of JUST riding. We've done very little desensitizing work and almost no ground work except for warm-ups, but most of the time I just saddle and get right on.
We even thought for a while that something might be physically wrong with her, but after several vet checks and a hiatus from riding at a trot or canter, she seems to be fine. Even lunging she doesn't seem quite as sore/hesitant.
So it is a little disappointing to go to the point where I can reliably tack up and mount without issue, and then get stuck where we can't canter together.
I am investigating some ways to resolve the issue, by going back to some riding fundamentals that I think we rushed through on our way to start canter work. I read Centered Riding, by Sally Swift and got taken to SCHOOL! Wow there's so much I don't know about riding properly.
So while the plateau is very frustrating, I think it will ultimately lead to better riding for us in the long run. Here's to hoping.....