My wife tried that when I brought my first handgun home. I believe her comment was:
"I WILL NOT HAVE A HANDGUN IN MY HOUSE!"
To which I responded:
"Your mother is 2 hours south, have a nice trip."
She stormed into the bedroom, slammed the door, came back 1 hr later and never brought it up again.
Gotta let her know straight up that your ability to protect her and your children is valued ABOVE ALL ELSE, even your relationship with her.
Or you can go ahead and place your scrotum in her purse now where it will reside for all eternity.