First let me say that you are a nice nurse!!! I am sure other nurses would have tore the student a new one and rightfully so. The student in question was not acting like a Student Nurse since she was performing without supervision AND doing so without thinking (assessing the patient before deciding to feed/potentially kill the patient).
I find this entire situation to be odd. My class has not started to actually touch patients yet because one thing we are having drilled in our heads right now is that WE ARE TO DO NOTHING WITHOUT OUR CIs right behind us. They have the license, we do not!
We are also not allowed to perform interventions without telling our CIs why. If we cannot explain why we are going to perform the nursing action to include feedings, then we cannot perform the action. This of course must occur AFTER we have assessed the patient (we are not allowed to take the word of anyone including our instructors).
By the way, we are not allowed to treat the staff, who may be future employers or co-workers, like dirt! We are to represent our program positively, which means we must act and dress like professionals at all times.