I wonder how many people have killed people and spent no time in jail? I also wonder why it's different to drop a sack of kittens off a bridge, or stick a poison needle into them?
anthropomorphism:
n.
Attribution of human motivation, characteristics, or behavior to inanimate objects, animals, or natural phenomena.
Genesis 3: 21 ... The LORD God made garments of skin for Adam and his wife and clothed them. 22 And the LORD God said, "The man has now become like one of us, knowing good and evil. He must not be allowed to reach out his hand and take also from the tree of life and eat, and live forever." ...
Mankind's dominion over the animals is by sacred appointment. Like any other gift from the Divine it can be exercised responsibly or abused. Certainly animals are not human, but that, in and of itself, does not sanction their wanton slaughter.
“The just regardeth the lives of his beasts: but the bowels of the wicked are cruel.” (Proverbs 12:10).
I don’t disagree that great injustices are done every day, over human on human crimes. Those injustices—by lack of punishment—do not make this girl’s punishment unfair however. Leniency (or even injustice) for one, doesn’t mandate leniency for another, as true justice is on a case by case basis; this girl is getting less than she deserves, IMHO.
It’s a fact that psychopathic murderers of people almost always start with the torture and killing of helpless animals. Time in prison—with psychological counseling—may keep her from doing much worse.
“A righteous man regardeth the life of his beast: but the tender mercies of the wicked are cruel.” (Prov. 12:10)