The decision to murder Farzana was taken by her own father and brothers.
It is the mysogyny of Islam that makes it possible for men to think it is a virtue to dispose of their own daughter as though she was their personal possession.
Read the account in the OT of the daughter in Sodom being given away by her father to be raped and murdered. Why should we be surprised? Eve was created as an afterthought. The Law forbid a man from coveting his neighbours ass or his field of his wife or anything belonging to his neighbour. It permitted a man to murder his wife if she didn't bleed on his wedding night. This is the culture that makes these attrocities possible.
The status of women in Muslim countries, and even in Western ones, is a disgrace. Until Muslim boys are raised to understand that women are their equals in every regard this will continue. While the pedophile prophet Muhammad contines to be regarded as a paragon of virtue nothing will change.