A very very very rare thing- when a mother kills her own children. You cannot hold that to the standard.
But don't you have to wonder about the emotional stability, and moral compass of someone who would propose such a grotesque oddity as a "case in point?"
That's what can happen when you are raised by a so-called born again parents who physically and verbally beat the crap out of their children in the name of God. BTW, I'll match my moral compass against anyone at anytime.