That's my plan: I'll have her as a trail horse for year or 2. Then I'll try to find some nearby horse events and ride there - no trailering. I'll see just how nervous she'll be with things happening around her and all the horses she doesn't know. If she'll accept it and be calm after few events then I'll start to look for a good airy trailer for 2 horses (so she won't be alone in it) with windows. And I'll give her time to adjust to it. At first just to be in, then driving her on our property and when she's calm we'll start taking her further away with trailer and then doing trail rides. In some time will start going to shows.
If she doesn't calm herself after visiting few events (before trailering), then we'll do just trail rides.