In the result of the suffrage movement, women were granted the right to vote yet in the early 20th century. However, it was still weird to see a married woman working back then. Things changed during World War II when women massively entered the workforce. They occupied factories and offices, some went directly into the military service. The US Air Forces had 60% of women.
During the war, it was essential that women supported domestic industries. There was a lack of workers everywhere, and women eagerly filled the vacant places. The felt entitled to perform their social duties and prove that they are no different than men in the society. The impact women made on the wartime economy changed traditional gender roles and their perception. Since the Cold War, it was not weird to see a married woman working anymore.