Zinaida Gina (Don't call her Zin, that's her brother's name.) always had a penchant for costume design and making, and worked hard on becoming one of the best in the business, ranging from custom dime store costumes to ones used in movies. It's her passion, and she takes it seriously. At least, as seriously as it need to be given that she makes very good (or convincingly cheap looking) costumes of stuff like werewolves or snake men or whatnot. 

She's a confident bird, if a bit tactless and indecent. Outside of work, she largely keeps to herself outside of a few close people. She's also rather smart, as she has a fair amount of experience with chemical engineering, and in fact was considering a life of crime with her brother. However she decided to take up an honest job. 

Not many know how she got her mechanical arm, though. Stories vary wildly, although some seem to agree that she there's more to her background than she might let on.