If it’s possible to treat your female non mahram patient without touching then you are not allowed to touch but if its really necessary then you may use gloves and if it comes the condition that you have examine private parts then you have to use mirror also if your discussion requires sexual advices then then there must not be any indication or intention of lust then it’s ok. Mostly if possible you may call any attendant with your patient to avoid any unwanted situation. Jazakallah