She reliable and can be mature at times. She is also hyper at times. A brave, 19 year old girl, Ellie has grown up in this harsh world and it is all she has ever known. She's an orphan who was raised in a boarding school run by the military within the bounds of the quarantine zone.

Ellie is described as "mature beyond her years" as a result of the circumstances of her environment. She is characterized as strong, witty, and "a little rough around the edges". She has emotional trauma.