@ orathaic
"I know, a simple safety catch might have saved a [life]."
It's not that simple. I'd have to know what kind of handgun she had, but a surprising number of modern firearms lack safeties for a variety of reasons. In many cases, it's an unnecessary redundancy. Glocks, for example (a popular choice for police officers and concealed carry permit holders) are designed without a safety catch, because the gun has a "double-action" trigger. In other words, the trigger accomplishes two actions: It pulls back the hammer/striker *and* releases the hammer/striker, hence performing two distinct actions with one muscle movement. This makes for a "heavy" trigger pull, which is viewed as a safety feature because it is impossible to pull the trigger without applying direct pressure to the trigger and it is simpler to operate for inexperienced shooters, so the shooter won't make a false move under stress (i.e. drawing and firing on a mugger without having to screw around with disengaging a thumb safety in between the drawing motion and the firing motion). Most double-action firearms will not discharge when bumped or dropped. The disadvantage is accuracy, as it is almost impossible to pull a heavy trigger while keeping the weapon precisely on target.
In contrast, a "single-action" trigger *only* releases the hammer/striker, which must first be manually cocked by the shooter in order to fire. The advantage is accuracy (because single-action triggers are always "lighter" than double-action triggers) and the disadvantages (depending on the firearm) are safety and simplicity. Most single-action semi-automatics (such as the legendary 1911 family) incorporate one or more safeties in the design, and it is generally considered "safe" to carry a single-action semi-auto in a "cocked-and-locked" configuration. Additionally, a single-action with a thumb safety is just complex enough to stump less-intelligent ne'er-do-wells. There's been documented cases of people legally carrying 1911-style pistols who were disarmed by thugs, but their lives were saved when the thugs couldn't figure out how to fire the pistol, because there's more to firing a 1911 than simply pulling the trigger, as is the case with a double-action.
My buddy has been CCing a 1911 every day cocked and locked since he turned 21 without incident. I also carried a 1911 in the same configuration for years, but I recently transitioned to the striker-fired, double-action only Smith & Wesson M&P 45. My M&P is equipped with a thumb safety, because I am used to carrying a 1911 and consequently sweeping the safety off is part of my well-rehearsed "draw" movement.