This is a policy issues that is not decided by an individual nurse. This is an issue for your Principal, superintendent, school board, school district attorney, state school nurse consultant, and ultimately your state Board of Nursing.
All who have accountability need to weigh in. It may not even be in line with regulations in your state.
You can find your state school nurse Consultant:
http://www.tjcats.net/nassnc/040817/...c_members.html
Your state's Board of Nursing:
https://www.ncsbn.org/index.htm
I did a search of the literature and cannot find any studies or articles that talk about IM Versed outside of an acute setting, nor to children. If this order is accepted, be sure you have a very tight policy on who is to monitor, calling 911, Bag and mask, oxygen etc. What is your EMS response time, distance to hospital?
Good luck - let us know the outcome.