She is one sick puppy...!
I don't even know if help would do her any good...!

As a parent that has gone down the path of rearing teenagers I can understand the urge to eradicate the mouthy know-it-all puppies.
I often had the desire to strangle my teenagers but never acted on it.

Considering how the laws have changed since most of us were teens, a lot of parents are hesitant to attempt any form of discipline for concern of being arrested.

Not knowing this family, all I can say is instead of killing them, IF they were that bad and acted like they were her equal, she should have put their azzes out and made them fend for themselves.

Another alternative to killing them, could have been making them pay for their own keep.

To me killing is what a parent does when their back is literally against the wall.

Such as dealing with a drug crazed teen.
Dealing with a teen that threatens the life of everyone in the household.
Dealing with an physically abusive teen.
Dealing with a teen that has tried and failed to kill before.

But for mouthing off, no.

Just punch them in the head until their eyes cross and they realize that you are the parent and they are the offspring.
And that they owe you parental respect just as you owe them respect.

Yes punch them until they eyes close, and there are other punishment out there she could of use, like tough love, but not kill them, that is so sad.