Llaca has worked as a journalist for the publications Nuevo Milenio and AM de Querétaro, where she wrote the daily Mi Ciudad column for ten years. She also wrote the fortnightly column Detrás del Frente for Expansión magazine. She edited the monthly magazine Ser y Estar and was a founding partner of the advertising agency Pauta Persuasiva. She was a 2003 fellow of the Gabriel García Márquez Foundation for New Ibero-American Journalism in Cartagena, Colombia, for her work as a journalist. Her stories have been published in various anthologies, including Azul, ventanita de cielo, and in the magazine Maga de Panamá, in the book Querétaro en su tinta, in homage to the painter Restituto Rodríguez, and in the book México Noir. Furthermore, she written for the stage and has worked in radio, and for ten years led a literary workshop. Her first novel was entitled Cuerpos en renta (Ediciones B, 2010). Llaca won the ninth Una Vuelta de Tuerca National Detective Novel Pruze for La simetría de los árboles (Planeta, 2016). El llanto debajo del llanto is due to be published in 2021 by Planeta.