Mary is a young woman that sports a pair of shorts and a tank top. She also wears boots that cover most of her legs.
As happened with Poison and Roxy in the original Final Fight game, Mary and Eliza were replaced by male characters called Robert and Leon (clothes with white and violet blue colors in the case of Robert, black and orange attire in the case of Leon) in the first versions of the game released worldwide. In the series Leon (レオン?) is her brother, and they get along well.
Mary takes care of her health to maintain her good appearance, liking to jog in Metro City's Bay Area. She also likes cleanliness, always keeping her room organized. When Mary was a child, she wanted to become a florist.
Due to her running exercises, her legs are strong, allowing her to deliver powerful kicks. She also attacks with knives at high speed.