The only thing I think should be mentioned, too, is the connection between your hand and your horses mouth.
She tends to tilt her head to the left, so try to keep her more evenly on both reins (ride figure eights or switch between shoulder in and renvers or so).
I know it is really difficult to keep the reins sorted riding with a double-bridle, but sometimes your snaffle-rein is loose and the curb-rein is too strong, so try to work on precision with the reins.
You look like a very sensible rider and I am impressed with how you handle your lovely but excited horse. Great job!