Someone anonymously pointed me at this (at least I assume that’s where they were thinking of, they didn’t actually leave a link).
If you disagree with the death sentence, go sign it. 17-year old Nazanin killed a man, one of three who was trying to rape her and her cousin. Apparently, Iran has signed the International Covenant on Civil and Political Rights and the Convention on the Rights of the Child, in which it agreed not to execute anyone under the age of 18 (I haven’t checked this) but that didn’t stop her being sentenced to death by hanging for defending herself.