I would try to bring her to showgrounds as much as possible and get her into the ring as much as you can. Perhaps putting her on a calmer on the lead up to a show would help just to settle her head? Very best of luck to you😊
I have a TB gelding who used to jump out of his skin when we took him out to events but at home he was really quiet, I took him to quiet training days and just took all the pressure completely off the first few outings and then started asking him to do more when out and now after about 6 non stress outings he's now really good when I take him to comps. Probably not the best answer but good luck and I hope this helps.
Would it be possible to take her to the place to where some of the shows take place when there is nothing going on? Might help her realise there is nothing to stress about as she's already been there and nothing bad happened :)
Take her away from the excitement if you can, and take it slowly. Try your best to do everything the same way you would at home. Keeping yourself and your anxious levels down can help, but that can be tricky. Having a good helper or friend/parent that you can chat to to keep yourself calm could help. Good luck :)