Grandma and grandpa were divorced when he was eighty. So forty years doesn't mean she'll definitely stick around. She can change your life as much or more than a SD shooting, without leaving the comfort of your home. Then there is the domestic violence thing,surprisingly easy to invoke, a very real threat, which will answer the gun ownership question once and for all. When you do risk assessment, put it all on the table. You could lose your home and loved one(s) with no shots fired.
Perhaps the thought of harm to another to save them is not worth it to them.
The obvious problem with that viewpoint is you're at risk as well. Then it comes back to you. Choose wisely.
What would I do? I'd carry discretely for myself, and if necessary promise to only defend myself, but cross my fingers, cause I never was much good at lying. I found early on, if you don't show people, they don't know you carry.
The business man next door asked me if I carried. He was surprised when I snaked my BG38 out. He carries a Diamondback. Who knew?