[11] In 1938, believing that education was the main weapon to mold the minds of the future, Aboim Inglez then started a school with her husband, Colégio Feminino Fernão de Magalhães (Ferdinand Magellan Women's School) in Lisbon, that promulgated a secular, progressive and social education, where you could find in the same class students of different sectors of the Portuguese society.

[15][16] She was also a member of the Associação Feminina Portuguesa para a Paz (Portuguese Women's Association for Peace -AFPP), militating alongside Virgínia Moura, Francine Benoît, Maria Lúcia Vassalo Namorado, Manuela Porto or Elina Guimarães, and supported the presidential campaigns of the general Norton de Matos, traveling the country speaking at election rallies in most major cities and giving speeches in popular assemblies, of the mathematician Ruy Luís Gomes, of the painter Arlindo Vicente and of the "General Without Fear" Humberto Delgado.

[18] In March 1942 her husband died, making her a widow at 38 and with 5 children to raise, and due to her social and political activism, Maria Isabel Aboim Inglês started being repressed by the Estado Novo, having her name vetted by the Ministry of Education after being approved by the Council of the Faculty of Letters to teach History of Medieval Philosophy.

She continued to act and give speeches against the fascist regime, holding meetings with Bento de Jesus Caraça, Francisco Ramos da Costa, Luís Hernâni Dias Amado, Mário Soares, Maria Lamas, Gustavo Soromenho, Luís da Câmara Reys, Manuel Mendes, Mário de Azevedo Gomes, Maria Palmira and Manuel Alfredo Tito de Morais, among others, in her house,[19] and was called "the indomitable" by the poet José Gomes Ferreira, even though she had the support of some professors that tried to appeal in her defense against the Ministry, in 1945 she was fired for political reasons by the Faculty of Letters and on December 13th 1946, she was arrested for the first time, being accused of being "a communist element", having been released on bail the next day.

Unable to teach, she set up a dressmaker's workshop, gave private lessons, did translations, not signing anything under her name as she was afraid of being boycotted by the publishers.

[26][27][28] During the trial of Isaura Silva, on July 15 1954, Maria Isabel Aboim Inglês, that was present as a defense's witness, was threatened, after having protested against the presence of PIDE agents in the courtroom.

[29] Having maintained contact with teachers, writers and journalists persecuted and watched by the fascist regime that fled to Brazil, like Manuel August Zaluar Nunes, Joaquim Soeiro Pereira Gomes, Manuel Rodrigues Lapa, Agostinho da Silva and Jaime Cortesão, in 1953 she was invited to teach Philosophy in a Brazilian university, however, the regime once again denied her passport's emission, informing her days after she auctioned off a big part of her belongings, being reported that António de Oliveira Salazar himself answered her appeal with the phrase: "She is a woman, she should sew socks".

[35] Posthumously, after the Carnation Revolution, her name began to appear in the toponymy of several Portuguese municipalities, such as Sobreda (Almada), Alfornelos (Amadora), Pontinha (Odivelas), Belém (Lisbon) and Alhos Vedros (Moita).