She waited way too long. On the opposite end is the officer who shoots the guy standing still in the original position just because they are holding a hammer 60 feet away. But in this case, as soon as this guy was running toward her then she should have blasted him away.
My guess is that she never learned that her gun is a tool, just like a hammer.
Remembering the man who’d famously previously physically attacked a police officer, reaching recklessly into the squad car to do it, then later was shot while charging at that same police officer, falling forward, short of reaching the officer, then dying. Can’t remember his name or the other circumstances, someone else might remember that.