Although a .38 might have a little too much recoil for an 80 year old woman. Perhaps a .22 would suffice.
I have always wondered about the reference to carry a sword and then have the rest of the references be so disproportionate to being passive. I believe we have a choice, to use it or not. He said that those who live by the sword will die by the sword, and this is confirmed in Revelation. His choice was to lay down His life voluntarily. But why would he allow a sword to be present at His arrest? I believe it brought Him hope because it reminded Him of the time when He returns to rule the world and then He will give the command for His armies to use their swords. It will be soon, and there will be no previous coming.
.22 works if the ammo is prepared properly. Hollow point, drilled deeper, poison inserted, a drop of wax to seal it in. One hit = one kill.