Wagtail
Horse servant
I think that if the owner is doing it during a crisis or because she is severely depressed, then putting the horse down will only end up coming back to haunt her. She may be racked with guilty which would hamper her recovery. IF the horse is rideable and healthy/sound, then I think she is making a bad mistake at a time when she is not able to think rationally. She is thinking in extremes. It will not be good for her in the long run.