Could you point out which picture you think her hands don't make sense? I am curious. The only thing I see there is at times the elbow comes away from the body, so if one looked at her from above, they would see a broken line to the bit, where the elbow stuck out.
I won't go into depth because this isn't my area but you need to make sure your reins and arms make sense. In some of these, your arm is too low or too high so it isn't really working for you.. just creating resistance in your horse.
Your overall position is pretty good. But sort out your contact. She looks a little stiff in the "hunt coat" pictures too. In the others when your arms make sense (as in follow the bit, using your body correctly) she seems very happy and put together.
Will go through each photo and give a quick opinion on the arms. ****please keep in mind I know more about dressage position and way of riding than the hunt/forward seat position and way of riding****
But since you asked, tinyliny. Here goes. (I wrote these mini critiques backwards so if you get confused read from the bottom up to see my train of thought lol)
In the first picture, her hands are lined up to follow the horse, without jabbing, at the trot. Only thing is it looks like her hands are kind of frozen on the horse's neck in position and slack instead of keeping contact so she'd have to give a little bit at her elbows to avoid jabbing the horse in the mouth and if she was doing so with contact, give a little bit more at her elbows so avoid jabbing the horse. But she knows what she's doing
In picture 2, the horse looks tense and stiff and that head is up and I see some signs of bracing. Her hands are low, and not in a position to follow the horse without jabbing (which may be why the horse's head is up in the first place, but this is again speculation and she'd have to do what I suggested below at a bare minimum to encourage the horse to relax and come down)
In picture 3, again notice how the horse's head is slightly more up and her hands are still down, not really in a position to follow the horse AS WELL and she may end up jabbing the horse in the mouth (may be why the horse's head isn't as relaxed as the pictures after this one.. this is speculation) so she would need to push her horse more forward and bring her hands up to encourage the horse to relax and come down again (paired with other things that I will not dive into)
In picture 4, her hands are lined up with contact to follow the horse (walk I'm guessing? Still haven't nailed the ability to tell which gait the horse is in without the tell tale poses)
In picture 5, her hands are are lined up on a slack rein and in position to follow the horse's movement at the trot so she doesn't end up jabbing the horse in the mouth.
The last picture her arms are working correctly with the horse. They aren't bracing, they aren't pulling up or down, they're moving at the same level and not impeding the horse. She can use her entire elbow to follow the horse's canter movement without jabbing the horse in the mouth.
Does that help?