You look great for your first time jumping!
Love that you are giving your pony the rein, in a beginner jumper that is important to stop you jagging him in the mouth as you find your position.
I have a few tips to add :)
When jumping, you want to incline your upper body forward, but not stand in the stirrups. The impulsion of the horse jumping is what determines how far out of the saddle you need to be. Over a jump of that size you can almost stay sitting in the saddle. If you shorten your stirrups a little, and just concentrate on going with the pony, you will find it a lot easier for you and the horse to jump, and for you to not need to stand in the stirrups.
You have wonderful heels and a pretty good lower leg position! Which is the foundation you need to jump well.
Lovely little pony you've got!
Attached a photo to kind of help.. I am inclined too far forward in this photo, but it gives you an idea about the length of stirrup, and the idea of not 'standing' in the stirrups.
ETA: Please don't critique my position, I already know whats wrong with it ;) And I'm only saying what I've learnt from a few instructors..