Theo, my sister was exactly the same way back in 1973.
I tried and tried to get her to take my advice seriously. No go!
She and I got along great, but I was a Marine and she was a nurse and she kept telling me “this isn’t a combat zone”. Everything is fine.
Well a few months later while on a road trip she and her friend were attacked. I had thrown my old Ruger 44 into their car with them before they left. My sis objected but I just got a bit forceful and she relented and allowed it to come along. 8 days later she and her friend were cornered by 2 men who broke the window of the little Dodge Colt they were driving and grabbed her friend, trying to drag her through the window.
My sister then remembered the 44 and was able to get it off the floor behind the driver seat. It is just lucky she was able to get the Ruger before she too was grabbed. When she brought up the handgun and pointed it at the man holding her friend he froze. He let her friend go and my Sister chased them off. No one was hurt badly and no one killed, but that was the moment the light came on for them both. It was the beginning of the end of her "liberal Hippie" period.
Ever since then my sister is a pistol packing lady. She has even turned down a job once when they told her she couldn't pack. She later got the exact same job in the same place when they decided she could keep her gun in her purse. (about 2 years later)
The reason for the story is simple.
Sad as it may be, the only thing that is likely to change your wife’s outlook on personal defense is to survive an attack, or be close enough to one that responding to violence with the use of counter-violence is no long just a theory.
When someone is primarily motivated my emotion no amount of logic or reason will make any difference at all. This is a very sad fact about human kind, but it is none the less a fact.
I would be praying to the Holy God that she either never has to be involved, or that she is not harmed when it happens the first time. But God is the only answer to this potential problem you have at this time.
May He give you wisdom.