Have you taken yourself to a chiropractor yet? This is often a good place to start when our horses seem “off”.
Doing some lunge line lessons with an instructor experienced in doing this can also help you get a better feel if it’s you or your mare.
Is she equally strong on both diagonals, and do you post both diagonals equally? Posting the weaker diagonal more than the stronger side can help strengthen her weaker side. This is best done on long fairly straight tracks.
A good dressage instructor/trainer should also be able to help you with exercises – both ground work and in saddle – that will help gymnasticize and strengthen your horse.
Patti Woodbury Kuvik