She looks like she is trying to get a bit more rein from you because of how tight they are...Yes you want contact, but I think you have a tad too much. This might be the reason that she stuck her head out instead of dropping her head and basculing properly....?
IMO, your stirrups look more hunter/jumper-ish then eventer length. (I am not an eventer though so not completely sure about this.) Your leg looks like it has slid back a little bit. This picture angle also makes it look like your arms are literally resting on the mares neck. Your 2-point looks good otherwise.
Kudos for the boots as extra protection on a green horse.
If you want a "better" critique, a square side on picture is better then an angle like this. Can't see what your leg is truely doing, nor your bum and back. :)
I think you need to give more or have a looser rein it looks like she is not happy about that bit hitting in her mouth..if you give more she will be able to round out more over the jump. I think your lower leg looks good, but your butt is too far out of the saddle and maybe open your shoulders a little more. Other than that you look good, and great job getting that mare to jump a log on only 2 weeks of work.
The angle of the picture makes it a bit hard, but there are some def things that stand out.
For xcountry you def don't want to be this much out of the saddle. I'd suspect you're gripping with your knee and your heels are up. You want to sink your weight into your heels and allow the horse's jump to close the angle in your hip.
Your horse does look super green... or it's the blue eyes, but he def doesn't look so sure of his job yet. I don't necessarily have an issue with your release, maybe a smidge more forward or down, but it's doing it's job of stabilizing your upper body.