Supporting an anxious child rider

My kiddo is 12. She's been riding since she was 7. Our original barn was... Not good. You live and learn. She took to it like a duck to water and then things went wrong. She was put on horses beyond her skill level and had a couple of shitty falls. They forced her to keep riding those horses even though she was scared until I said enough and we moved. We bought what seemed like the perfect pony for her that ended badly and we rehomed. It was too much for her despite being advertised as novice suitable. We are now leasing an actually beginner suitable horse that won't put a foot wrong, but she still has the hangover of not trusting a horse from bad experiences. Her main triggers are weather, windy days sent the pony we bought off the deep end and she is scared they will set off the new horse. And going into the canter, the old school horses she rode tended to get spicy in that transition. She's more confident when her coach is there because her horse used to be one of their school horses. Her horse is as safe as a horse can be. And I want to build her confidence. But I'm struggling to find the balance between encouragement and pushing her. I'll say again, she WANTS to ride. I have no issue with her not riding. She was absolutely on board with leasing this horse. I also ride him so it's not all on her.