
As she has only just started in competition it could be a lack of confidence, I would guess she is getting a bit worried and is trying to find a distraction to take her mind off it.
You may have to throw a few classes to get her over it, or use a pay on the day ring and just concentrate on the set ups.
I am assuming you are setting her up at the start in a wait. Drop that for a while and just go up to the start line with her, without going over the top with your voice, bend down with her and say are you ready, then take off with her saying let's go, or similar. She will not have time to get distracted then, you will have contact with her to reassure her and keep it all flowing.
If you can find a practice ring, I would just do one jump, pull her out, plenty of praise and do it again. I am sure the judge won't mind if you say you would like to do three or four starts rather then the whole course.
Hope this helps,
Sandra