The primary care practitioner in your school's health clinic has a master's degree and is authorized to perform exams, conduct diagnostic tests, and in some states may also prescribe medications. She is a .

Nurse Practitioner.

Explanation:

This is the  advanced nursing practise designed to cater for shortage of physician especially  in the USA; Canada and some other western countries. They are registered nurses equipped with skills of  mid-level practitioners, and therefore  were  authorized to design treatment plans, provide diagnosis, interpret results of laboratory tests, and general care coordination. However their training does  not involved  complex clinical conditions, and are not restricted to work under physicians, but most work under their supervision while  few are independent practitioner

.

It requires the possession of a graduate degree of 1 -3yrs study duration in addition to  the registered nursing certificate to be proficient in the field.