She called 911 and tried to have the proper authorities handle this problem. (Of course they were too slow.)
She retreated into a bedroom
She had a child with her that needed protection.
The guy broke in the door, clearly showing violent intent.
She fired just one shot. Just the minimum to protect herself and the child. 911 operator must have heard the whole thing.
And I guess the "do-gooders" will insist that she should have somehow handled it differently.
I am glad that she took care of business with this guy, but I am bothered by the fact that her poor child had to be exposed to this kind of incident. Lord knows what else the poor kid had witnessed.