One granddaughter is in high school ROTC. I'm not sure just how this works but her's is Navy with Marine instructors. In any case she was recently promoted to PO3.
As I understand it, this is an E-4 rank. That is what her father held when he left active duty with a medical discharge.
Since she has been a straight A honor student since first grade, she might qualify for a full ride through college or even an appointment to an Academy.
Not that I'm a proud grandfather or anything.