She's logical... if you twist your head to the right and squint. She certainly makes sense in her own head. I really am working with the episode (and planet) Ariel a lot. That's where Jayne not only betrayed Simon and River, but Mal threw him in an airlock and was truly ready to let him die. He only relented after Jayne not only accepted that he was going to die but made his last request... that Mal make something up to explain his death so the others never knew he had betrayed them.