In the summer of 1934 she moved to a teaching post in La Pobla de Claramunt, where she lived until the start of the Spanish Civil War.
The objective of the association was to encourage women to collaborate with the republic by helping create a civic consciousness in a segment of the population which had not, until then, been interested in politics.
Yarza then joined the Esquerra Republicana de Catalunya (ERC) party to head the candidacy in the municipal elections of Bellprat.
Yarza moved to Barcelona to join the Council of the Escola Nova Unificada as a teacher after helping her substitute in La Pobla de Claramunt, Núria Maestre.
Once the fascist occupation of Catalonia was completed, Yarza went into exile in France where she survived as an iron presser and thanks to a grant from Spanish Refugee Aid.