After her retirement, Obregón continued to teach privately and began working with activists and organizers to improve the education system and political access of women in the country. She was one of the co-founders of the Asociación Nacional de Educadores (ANDE)(National Association of Educators) and she served on the Board of Education for San José. In 1943, she joined with students and women in the protests known as the "Women of May 15" to oppose prohibitions to women's political participation and press for suffrage. In 1947, Obregón joined Emma Gamboa and they organized a group of women including Clarisa Blanco, Rosario Brenes de Facio, Amalia Chavarría de Rossi, Claudia Cortés, Aurelia Pinto de Ross, María del Rosario Quirós Salazar, Etilma Romero de Segura, Cristina Salazar de Esquivel, and Marta Uribe de Pagés to demonstrate with around 5,000 other participants against electoral irregularities and fraud in the upcoming election in 1948. The elections sparked the Costa Rican Civil War and at war's end, women finally gained the right to vote and participate in politics.