Well here’s the good and the bad news-I rode the horse last night and she was generally fine.
I combined a few different ideas that have been provided in here (some I read after and will try to implement next time I ride her). I always have a whip but I also put a pair of spurs on. Beginning of the ride she certainly didn’t want to go in some areas but in the “safe” areas I just made sure she was alright with the spurs, worked on bending around the ribcage, did some dramatic leg yields leading with the shoulder first. Then I asked her to go near the stuff to check her reaction-she tried to stop but I gave her a little spur and she backed up a few steps, then went forward towards it and I immediately gave with the rein and scratched her withers. I did this a few times, then after that I went back to normal work and was able to circle by the things pretty successfully as long as I kept my leg on as we went past. Getting a dramatic leg yield towards it helped a lot. I did also make sure to get her into that corner that she’s so scared of so I could get off her there and gave lots of praise.
She definitely went around a little curled up with her neck today (this is something we work on every single time we ride her as it’s just her favorite place to be) but I didn’t want to throw too many things at her at once so I just let that be for now since the ride was brief anyways. But I like the idea of working her hard (within reason) in the safe spaces, and making the scary spots the places where she can stop and take a breath so she thinks better of those areas so I will be implementing that in the future too!
But I think overall, the mare is just worse for the other rider. There was even a very loud noise while I was on her and near the scary stuff (someone accidentally dropped something), and she certainly spooked but just took a couple steps then stopped. I really expected much worse behavior from her last night after her other rider ended up getting off her the night before.
I do also agree with you all that it is kind of an iffy situation - thus far the mare has never once felt like she is going to rear but if she ever does feel like she’ll have a big reaction I’m not going to push it. I don’t really know how to explain it but when she does plant her feet and refuse to move she doesn’t feel like she’s going to explode at all. I like it less when she starts backing up, but she does that quite infrequently and I’ve been able to stop it quickly. But if I ever start to feel unsafe I’m not risking it, as I have my own horse to ride and take care of as well.
Truthfully-and I understand this is super unrealistic-I am hoping I can get a more consistent ride on her when the other rider’s lease ends, which will be later this year. I won’t pay to ride the horse so the owner would have to be willing to foot the bill so I don’t foresee that happening (although she does pay half her board right now and doesn’t ride her), but I do like the mare quite a lot when she’s going well. She’s quirky as hell and won’t suit most riders but I have fun on her. Best case scenario is her owner gets healthier and starts riding her and enjoying her all on her own of course, but unfortunately it’s not looking likely.