Wow!! I love the first horse you are riding!!! He/she is very sharp!!!
On the flat your equitation(from these pics) is basically flawless. In the second picture you are looking at the horses head which you don't want to do, but other than that you look amazing
You need to shorten your stirrup about a hole. Then you will have more of a base to work off of. Once you do that you want to bring your leg forward so that your hip is even with the end of your foot. I believe that you aren't pulling on the horses mouth but it is hard to tell because it appears that you have a longer rein. You want to move your hands up more on the neck, to give a good release.
Hope this helps!!!! and I love all your horses!!!!!!!!
It is not just a horse,
It is the one thing that keeps me from being just a girl