Welcome to The High Road, Liane!
I was antigun until around 1994, and for me, not knowing anyone into guns, I read EVERYTHING I could get my hands on. I wish I'd had THR back then.
Nazirite-This one is going to take a lot of prodding. Before you get her to the range (assuming you ever do!), tell her that while you respect her viewpoint (LIE!), doesn't she think she should be able to render a firearm safe if she happen upon one, or if some children should find one? If she succumbs to that logic, show her how a gun works (no ammo) and how it is unloaded. Get her to go through the process with her own hands.
If she refuses to learn, then she is truly hoplophobic, and you're wasting your time.