She would help Snape complete the potion, for who was she to prevent the world she lived in from being rid of a madman? She would contribute to the war effort, but she would no longer be working for the Order of the Phoenix. She hadn't thought the day would come that she would outgrow the Order and feel the need to move on, but she had arrived at that day. If they would not support and accept her, then she would not work for them. Her anger at their betrayal had driven her away, and they would have nobody to blame but themselves.