Remind your mom that people absolutely used weapons to defend themselves in the Bible.
You could also ask her if she wears a seatbelt or follows roadsigns or does any other basic safety precautions. If so, why? Doesn’t she trust God?
Sorta makes sense if you think whatever happens to you is just gods will, kinda the same reasoning some people use not to seek medical attention when their sick. Its seems like a bit of a weird thing to balance of taking control and precaution in your life while saying god ultimately has control over everything and you shouldnt be able to change his plans.
God didn’t let us discover medicine by accident. I’ve never understood the mentality of not using the resources he gave us and yet saying things like “God will provide“. He already did provide, genius.
It’s like that old joke about the guy on desert island who turned away a boat and a plane that came to rescue him because “God will save me“. He ended up dying and when he went to heaven he asked God why He didn’t save him and got replied “I sent you a boat and a plane you moron“.
Bottom line the earth is the Lord’s and all it contains. There’s no such thing as “God versus The World’s™️ medicine“, it all belongs to God.