Ferrow is a supporting character in the anime Gunslinger Girl, serving as a senior operative and field leader within the Social Welfare Agency's Section Two. She is an adult woman, recognizable by her short black hair and professional demeanor, often dressed in a business suit with a necktie. Her name, which means iron in Italian, may be either a nickname or her surname, as her first name is never revealed.

In her role, Ferrow is a trusted subordinate of Lorenzo, the director of Section Two, and has been associated with him since before the agency was officially founded. She acts as a key logistical and tactical coordinator for the agency's operations, most frequently providing direct combat support and operational backup to the handler Jose and his cyborg partner, Henrietta. Her position demands efficiency and professionalism, and she is known for her serious and often brusque manner. While some might find her unfriendly, this demeanor is generally understood among her colleagues as a manifestation of her strict, no-nonsense attitude toward the dangerous work of the agency. She is one of the few non-cyborg personnel consistently seen involved in field operations alongside the agency's primary assassination teams.

Beyond her professional role as a coordinator and agent, Ferrow has personal connections to other members of the agency. She has a significant relationship with Amadeo, another male operative within Section Two. The nature of their relationship is strongly implied to be more than collegial, with evidence suggesting they are cohabitating partners. This is supported by their behavior during missions, such as sharing a room at a harbor hotel while providing security for Jose and Henrietta on a vacation to Sicily. Her domestic life is touched upon through anecdotes. Colleagues note her fondness for cats and her habit of humming while cooking, such as when she prepares baked dishes like gratin. These small details contrast with her severe professional exterior, revealing a more complex individual who maintains a semblance of a normal private life outside the agency's dark activities.

Ferrow's character is defined by her loyalty and experience. She does not undergo significant personal development or dramatic change throughout the series, instead functioning as a stable, reliable constant within the volatile environment of Section Two. Her primary motivation is the effective and safe execution of the agency's missions, and she demonstrates a deep sense of responsibility toward the handlers and their young cyborg charges. As the leader of the general Section Two employees, she is a figure of authority and competence, ensuring that the complex logistical and security elements of the agency's covert operations run smoothly. Her abilities lie not in superhuman combat like the cyborg girls, but in tactical planning, field leadership, and marksmanship, making her an invaluable asset to the agency as a whole.