Fabiola Iglesias is a young Venezuelan woman who serves as a maid in the wealthy and powerful Lovelace family. Her first appearance is in Roanapur, the lawless Thai city where much of the story takes place, as she seeks out the Lagoon Company for assistance. She is the second combat-capable maid in the household, following the far more infamous Roberta, whom she greatly respects as her senior and mentor.

Standing much shorter than Roberta, Fabiola is often mistaken for a younger or "mini" version of the killer maid due to her similar black French maid uniform. She has a tanned complexion due to her South American heritage, with dark green hair and eyes. Her youth is evident not only in her stature but also in her demeanor, which is generally more open and less cold than Roberta's, though she is far from naive.

Fabiola's background is rooted in the barrios, or slums, of Caracas, Venezuela. She comes from an extremely large and poor family, with ten siblings making for eleven mouths to feed. As there was little work available in the slums, she used a distant relative's connection to a farmer on the Lovelace plantation to gain employment as a maid. Despite her difficult upbringing, she speaks of her family with a sense of love and normalcy, recounting an incident where her mother beat her severely for stealing a CD player for her younger brother. While someone like Revy might see this as abuse, Fabiola interprets it as a harsh lesson born of love and a refusal to tolerate sin. Her early life in the barrios also exposed her to capoeira, the Afro-Brazilian martial art that she learned by watching others practice and then trained in on her own, incorporating it into her unique fighting style.

Personality-wise, Fabiola is a study in contrasts. On one hand, she is dutiful, polite, and dedicated to her role as a maid and protector of the Lovelace family's young master, Garcia. On the other, she is fiercely capable in a fight and is not afraid to use extreme violence when necessary, though she actively tries to avoid it. Unlike many of Roanapur's hardened killers, Fabiola is genuinely reluctant to take a life. She becomes visibly shaken after her first experiences with killing, a fact that Revy notices due to her trembling hands. This reluctance is not born of weakness but of a strong personal moral code. She views killing as a last resort and becomes enraged when she witnesses unnecessary cruelty, such as when Revy executes a wounded and defenseless soldier. This moral line in the sand sets her apart from nearly every other gunman in the city.

Her primary motivation throughout Roberta's Blood Trail is to find and save Roberta, who has gone on a violent rampage of revenge for the assassination of the Lovelace family patriarch. Acting on behalf of her young master Garcia, she travels to Roanapur to secure the help of Rock, believing his unique perspective and negotiation skills are the only hope of bringing Roberta back without further bloodshed. Her mission is to prevent Roberta from destroying herself and to bring her home, a task she feels a deep personal responsibility for as the only other maid with combat training.

Fabiola's key relationships define her role in the narrative. Her most important bond is with Garcia Lovelace, the boy she is sworn to protect. Her loyalty to him is absolute, though it lacks the same obsessive, almost romantic quality that Roberta's loyalty possesses. She cares for him deeply and acts as both his guardian and his faithful servant, often trying to manage his more headstrong decisions. Her relationship with Revy is a major source of development and conflict. The two are foils for each other, both young women from brutal upbringings who have become skilled combatants. However, where Revy has embraced nihilism, violence, and a cynical worldview, Fabiola clings to her principles, her faith in family, and her aversion to killing. They clash over this fundamental difference, but there is also a grudging mutual understanding that develops as they work together. Fabiola holds deep respect for Roberta as her teacher and the head housemaid, and a significant part of her story arc involves witnessing the terrifying, drug-fueled monster Roberta has become and striving to reach the person she remembers.

Over the course of the story, Fabiola undergoes a subtle but important development. She arrives in Roanapur as a competent fighter, but the events force her to confront the true nature of the city's "dance of the dead." She is forced to kill for the first time, an act that leaves her psychologically shaken, proving she is not a natural-born killer like Revy. Her idealism is tested as she witnesses the brutality of the world, yet she does not abandon her core values. In the end, after Rock's risky plan to shock Roberta back to her senses succeeds, Fabiola demonstrates her independent judgment and frustration by shooting Rock with a fake bullet, telling him his cold, manipulative plan made him well-suited to this city of villains. This act shows she has learned from her time in Roanapur, becoming more hardened and pragmatic, but without surrendering her own sense of right and wrong.

Regarding her notable abilities, Fabiola is a highly effective close-quarters combatant. Her primary fighting style is capoeira, which she integrates with her firearm use, making her movements fluid and unpredictable. She uses a knife concealed in the heel of her shoe, a weapon she used to cripple an enemy in her first appearance. Her main firearms are two MAG-7 pump-action shotguns, which she conceals in her sleeves, and a China Lake pump-action grenade launcher which she carries on her back. These oversized, high-firepower weapons serve as a compensation for her smaller stature and her relative inexperience, allowing her to suppress or eliminate threats quickly. Although she is skilled and dangerous, her inexperience and reluctance to kill mean she is still outmatched by the most savage killers in Roanapur, like Revy or a fully-unhinged Roberta.