It is hard to see, I would like to see a closer photo. I like the breeching height as it is, but if Grace stands square it might be a tad too low, but it looks good so far.
The saddle is where I find it hard to see. It looks a bit too far back, BUT if your pony has a long sloping whither it is correct, I cannot tell, even zooming in. You don't want the saddle sitting on the whithers. Especially a saddle without a tree. If your saddle doesn't have a tree I would strongly recommend a pad. Does you harness have two girths? One to hold the saddle on and one to hold the shaft loops down. If it has two girths they should lay one on top of another. Your holdback straps are connected to the shaft loops so that might be pulling the outer girth back. You want to have the saddle as vertical as possible, but often times that is not possible because of horse size or confirmation.
She looks really cute in blue!!!
I would love to see a closer photo.
The best time to plant a tree was 20 years ago, the second best time is today.