This young lady may be very sincere and compassionate. What she lacks is access to anyone able to help her develop her logical facilities. That is what school is supposed to do. Give kids the raw material, ie facts, the history to understand perspective and the information about scientific method and research to allow them to dig into a subject they are passionate about and become informed. School has failed this student and many others.
Where are most mass shootings, gun free zones. Individual shootings are most prevalent in gun free communities like Chicago. What has been the effect on violent crime in communities with open carry? They have fallen dramatically. Would the gun laws you are proposing have stopped any of these mass shootings? No.
So what should we do to keep students safe. Make them open to carry permit holders and have at least one person armed to protect the students. Make their presence obvious and post signs. I think new school buildings should be situated adjacent to police stations. That would be the best deterrent.
My house is situated very close to a police station. It does not deter crime one bit. My neighbor’s vehicle was broken into last month. The number of vehicles that speed by going at least 10 mph over the posted speed limit far outnumber those that obey the speed limit. I could go on and on.