I'm beginning to get the urge to destroy her life.
Why do you want to destroy her life?
She killed my puppy which was my only friend
Your anger is justifiable. Maybe your puppy got killed accidently? You do not have any right to ruine her life.
She decided to kill him to make me mad.
It's very disturbing what happened to you and your puppy. But seeking revenge on this person is not going resolve your issue. If you believe she actually killed your dog you should seek legal counseling.