Eileen is a short, dark-haired caucasian woman. In her first appearance, she wore a maid disguise and later a typical hunter's outfit consisting of a shirt, trousers and a jacket. Like the Winchesters, Eileen also wears plaid shirts.

Eileen is deaf and was orphaned by a Banshee. She is a strong-willed young woman capable of holding her own. She was able to take Sam down by surprise and confront her parents' murderer with nothing but determination. She can be ruthless to enemies and friendly.