What I meant (and should have explained more carefully) is to stop her work before she starts to get sore. As for helping her, I would check with my vet first (I am too paranoid to not ask the vet) as to what s/he thinks might be best. No point in spending money on something that won’t help. You may just have to cut her riding time in half, or do something not too stressful, such as trail rides. I wouldn’t say retire her, just go more gently with her.
It is never the horse's fault