Respuesta :
You would want to talk to her in the back and use a moderate tone and show her the schedule showing that she was booked for a appointment another day and time. You then tell her that you are sorry for any inconvenience and that you will be expecting her on the right day of her appointment.
You can calmly approach them and show them a printed sheet with the time of the appointment and suggest writing down the times for important things or putting them in as reminders in their phone. You can relate to them and tell them their life must be stressful and that it is easy to become forgetful when you have so much to worry about.