I'm not liking how you are sitting in this picture. Your leg is really far forward and your but is really far back. I would (maybe) lengthen your stirrups a hole and then focuse on getting your butt forward and your leg a bit back. Your heels are also up, try to get them flexed down. It looks like you are holding your breathe..? Relax! I get really tense at shows, but once I relax I'm just fine! :)
I know NOTHING about saddleseat, but I would say work on getting those heels down! Get more bend in your arms too.
Your horse is SUPER cute, but I would like to see a change in her headset. I am in love with her tail.
Sorry if I seemed harsh... ):