Hermione should’ve done the bloody deed herself; she shouldn’t have allowed Draco to take all the burden of the killing, but truth be told, she was a coward. She didn’t have it in her to kill her best friend, even though that would’ve been just and merciful. Deep inside she knew it would only be right and that it was her duty, one that Draco had nothing to do with. She even loathed herself for not offering to kill Harry so that Draco wouldn’t have to do it. He would’ve refused without a single doubt, he wouldn’t let her go through such misery, but she could’ve at least pretended she cared about him enough to spare him from becoming a murderer times thousand.