Upon arriving in the Catalan capital, she initially worked in her uncle's workshop, but it experienced economic difficulties and was closed due to the Great Depression.
[1] During the 1930s, Estorach spent her days working in a factory and received an education in night school, through which she became involved in the trade union activities of the Confederación Nacional del Trabajo (CNT).
[3] That year, she also joined the Libertarian Youth (FIJL) and participated in the revolutionary committee in the El Clot neighbourhood, where she helped lead the resistance to the July 1936 military uprising in Barcelona.
[1] During the Spanish Civil War, Estorach organised soup kitchens and other mutual aid initiatives, and travelled around the Levante as a representative of the FIJL.
[3] She also established the House of the Woman Worker (Catalan: Casal de la Dona Treballadora) and collaborated to the Tierra y Libertad magazine.