The trainer has nothing to do with this horse and her attitude toward it is irrelevent. If her income is based solely on the students she has at this facility and the ability to train there then that should rightfully be her top priority. If the OP wants to inquire about the welfare of the horse, assuming that it is ldone with some tact, then I see no problem there but she should be prepared to be told to mind her own business. I would guess that the condition of the horse has been exaggerated but even if it hasn't, the horse is in a clean stall and is fed twice a day which is not neglect.