In Aranda de Duero Urraca joined the Navarrese troops commanded by and heading for Madrid. On the intermittent basis she served as nurse on the Guadarrama front; during breaks she engaged in propaganda work and threw herself into organizing Carlist medical services, mostly recruiting women as nurses and auxiliary staff. November 1936 back in Guadarrama she spent Christmas among the soldiers, but moved – still as a nurse - to the Northern front in early 1937, partially present during the Nationalist conquest of Vascongadas. In immediate vicinity of the frontline Urraca made a picturesque figure; apart from typical medical activities she dispensed cognac at arbitrary doses to the wounded. According to some testimonies, she inflicted her Christian compassion upon the otherwise fanatical Carlist soldiers and prevented Nationalists from executing the Republican prisoners; she also publicly defended some captured Republicans accused of crimes. Other accounts point to her cruelty and suggest that she was co-responsible for Nationalist atrocities, especially for executions of Basque priests. She is also quoted writing that the orphaned Republican children should not be treated the same way as the Nationalist ones.