If you can, imagine that Velvet has a very similar sentiment as you. She’s grown frustrated and imapatient too. There is something wrong. And it may be the culmination of many things that she can no longer ignore.
I have a very dependable gelding that doesn’t have a malicious bone in his body (most horses don’t, IMO, that’s a human characteristic). But yesterday he came very close to tossing me because he was trigger stacked and the thinking side of his brain shut down and his reactive side took over. He behaved in a way that is SO out of character for him that I swear once it was all over and even hours later that day, he looked like he felt ashamed and sorry for how he’d acted. (That’s almost certainly me projecting the fact that I felt bad for even putting him in the situation that took him over the threshold. My good, sweet buddy didn’t deserve that, and I 100% could have avoided the entire situation…my own arrogance/ego was to blame).
But I digress. The point is, Velvet may have so many “triggers” that have stacked up over her lifetime thus far that figuring out what they are and how to help her let go of each of them until she no longer has to resort to extreme measures to be “heard” when she’s upset…could take a long time and a LOT of patience on the part of the human.
It’s not what you wanted, I’m sure. If she’s meant to replace your former upper level horse, that’s a big ask for a troubled mare. If your goal is competing and her goal is to survive the day without someone pushing her past her threshold, I’d say that’s going to be tough.
Take a very close look at her feed (no carbs, starch, etc. for this girl…forage and a forage balancer, and some fat), turnout (24/7 if possible), management (socialization with other horses?), tack (saddle fitting, bridle type, bit type), and anything else in her daily life that could be adjusted to possibly remove some of the “triggers” from the extensive “stack” she’s dealing with.
Then, yes, the reproductive side of things. That can definitely be among the things she’s dealing with. Great that you’re getting that checked out.
If all else fails, maybe someone will want her for a broodmare. You say she’s got great bloodlines and is a nice mover and athletic. Maybe that’s her calling.