Morales was first sent to Cámus's unit, the 3rd Regiment of the Line, which was at the front of Chile's campaigns during much of the war. Although she officially was not a soldier and was not supposed to participate in combat, this did not deter her from fighting alongside the men of her regiment. Indeed, she was noted for her great skill with a rifle. She fought at the amphibious landing and fierce ensuing assault on a Peruvian position of the Battle of Pisagua on 2 November 1879 and at the Battle of San Francisco on 19 November. She was looked up to by the men of her unit for her selfless nursing of the wounded after battles. She also put herself at risk several times to save captured Peruvian soldiers from being abused by her compatriots.