A lightweight aluminum and steel model felt best in my female hands. I also bought a box of 38 Special Hollow Base Wad Cutter bullets and went home and learned how to aim, fire and handle the recoil. I carry the gun in a fanny pack for easy access. In addition I bought tear gas pepper spray and learned how to use that. A choice of options is very important depending upon the situation.
Some schools have armed security.
I know other teachers who possess guns. I don't ask because like many other real subjects available for debate, the topic is taboo. I asked my classes what they thought about the gun toting teacher idea and they told me the idea of some of the teachers carrying guns that they consider inept, didn't appeal to them. But, they thought that some of their other teachers should carry one. In suprising ways our older children are concerned, and actually take comfort in the idea of armed people in charge.