Your weight needs to come down the back of your leg and into your heel more. It gets stuck right about at the knee, which is too high. Open the hip, then the knee drops bringing the lower leg back underneath you more. Work w/o stirrups would help this.
Your wrist is bent in almost all the pictures. I see you are correcting the piano hands, but the wrist needs to be straightened as well.
In the picture where you are walking toward the camera...see how the horse is counter bent...that's on you. You dropped your left shoulder, brought your left hip and leg back and she counter bent in response. (Unless you were going for something specific here??)
Then in the second to last photo, you've done the opposite thing going in the other direction...so, you must be trying something when going down the long sides...what was it?
In the posting trot picture, you're behind the horse's motion and you can see as a result your leg is too far forward as you try and catch up to the motion. The other thing here is your hands are too high, which suggests to me that you haven't yet been able to separate your hand from your hip...independent seat...and that your hands rise and fall as your hips do.
Lastly, your arms are too straight in all the walking photos, having lost the bend in the elbow.