There has been a big improvement!
What I am noticing though is you are very locked in your hips. You need to have more of a "fold" at the hips. I always suggest to my students to go home and sit on a yoga ball, don't let your bum touch it though, just lightly hover over it and practise going into a two point. Its better if you can do it in front of a mirror. Just go from sitting tall to going into two point. Watch where your leg goes, allow yourself to open your hip angle and have a soft fold at the hips, pretend you are holding the reins, work on having your shoulders back, pull up in your tummy, elbows in and hands where they would sit in a release. Doing this will help you loosen up at the hips and feel your position. Then you can take this back to the barn and work on doing it on your mare.
Also set up trotting poles just slightly raised, go into two point going down the poles with a release and use your core to control the stride.
If this is clear as mud let me know and I will do a better description of it for you when I get home tonight
BTW your mare is adorable! I love her to pieces!