Hi PJ, I'll preface this with, I'm not dressage pro (but there are plenty on the forum). Your horse seems to be willing to learn and looks to be trying really hard. She seems very sweet!
One thing I saw was that you don't seem to have a steady contact with the bit, so she might be getting confused, causing her to raise her head and look for something else you might be asking. I also am learning (with a coach) to teach my horse to be round and something she impresses upon me is to relax and leave his mouth alone when he is doing what I ask. Maybe getting quieter reins will get her to stay round?
Off topic, but it looks like her rear legs are wrapped, but not her front?
I wrote a really long reply but my POS computer dropped it. I will try again, but maybe a truncated version.
Basically, try doing more of this at a walk first. I agree that you seem to have unsteady rein contact. At a walk you will be better able to follow the head and use the rythm of the walk to invite the horse to reach downward.
I can see you "fiddling" with your reins a lot. I know you need to invite the horse to reach down, but if you don't have enough contact with the mouth to be able to follow it, you will miss the place where the horse starts to go down, where you would follow softly so that she knows "yes, that's it"
The think you want is for the horse to both reach downward AND reach outward with an arch in the neck. You don't want her to come behind the bit, at all , not behind the vertical, not at all. Think more of her neck reaching forward in the way a horse will arch and reach forward to touch noses with a new hrose (the way they are excited).
Secondly, you wan the horse to step through with some push from behind. At a walk you can really feel the push . You visualize the horse kind of pushing through the "gate" you form with your reins and the bit.
Don't let your arms brace out at the elbow. Otherwise, you ride quite well and you two will be a wonderful pair.
Lastly. For such ayoung horse, give her a loose rein stretchdown a lot and mix it up to relieve boredom.
I like your horse. She looks like she's trying hard for you. There's just not much consistency there for her to seek. In most of the video, your line from elbow to bit is extremely broken. The few times it is there, your mare does try to seek contact. Your reins are too long, so it's like asking someone to push open a door that is still 3' away. You'd have to fall off balance just to reach the door.
At the walk, picture an invisible box in front of the pommel. The box is just big enough to give and take to your horse's head motion. Start with your reins in the proper position, in front and an inch or so over the pommel, bend in supple elbows with straight line to bit. Then keep them in the box. They are only allowed to move enough to follow your horse's motion. Resist the temptation to move them out of the box and fiddle with your horse's head. The idea is to provide her with inviting contact that she seeks herself. You get her to it by riding her hind end with your seat and legs. Once you get consistent contact at the walk, try it at the trot. Really concentrate on keeping them steady for her but supple like they are made of taffy. Good luck!
Thank you everyone. Everything so far has been constructive and helpful.
I'll leave you all happy to know the trainer was encouraging me to do the same and we worked on it at the walk for at least half of the lesson I just didn't put that in the video. The reason my hands are a mess (and I did fix them in other clips when I felt her being truly forward) is because she is the laziest horse to get going! Because she hasn't been under saddle for long, she hasn't yet (until today) grasped that she can indeed KEEP MOVING FORWARD with rein contact. Before today if you asked her to flex at the pole, she would, but only stay like that in the walk.
Oh and yes her back legs are wrapped. I did not have time to do the front.
You're one of those who do the "human side rein" effect. You also have a tendency to lock your arms when doing so. In fact, your hands are almost at your knees in some parts. If you want to encouage your horse to be "long and low" it would be good practice on your part to keep your hands up. If your instructor is telling you the best way to achieve "long and low" is to have your hands like that, I would find another instructor. It is a HORRIBLE habit that will just get you into trouble later on. Ask yourself this...How can you have good posture on a horse if your hands are stretched out? That just causes you to leand forward (which you can yourself doing) and hunch your back.