On 21 August 1940, Trotsky was assassinated in Coyoacán, where he had continued to live after leaving La Casa Azul. Kahlo's work has been celebrated internationally as emblematic of Mexican national and indigenous traditions and by feminists for what is seen as its uncompromising depiction of the female experience and form. She experienced pain in her legs, the infection on her hand had become chronic, and she was also treated for syphilis. Born near Mexico City, she grew up during the turbulent days of the Mexican Revolution and, at eighteen, was the victim of an accident that left her crippled and unable to bear children. Her paintings from this period, such as The Broken Column (1944), Without Hope (1945), Tree of Hope, Stand Fast (1946), and The Wounded Deer (1946), reflect her declining health.

Although their marriage was quite unhappy, Guillermo and Matilde had four daughters, with Frida being the third. To salvage what she could from her unhappy situation, Kahlo had to learn to keep still – so she began to paint. Particularly in the 1930s, her style was especially indebted to votive paintings or retablos, which were postcard-sized religious images made by amateur artists. Throughout the 1940s, Kahlo participated in exhibitions in Mexico and the United States and worked as an art teacher. Kahlo once again experienced health problems – undergoing an appendectomy, two abortions, and the amputation of gangrenous toes [204] [151] – and her marriage to Rivera had become strained.Regardless, the Louvre purchased The Frame, making her the first Mexican artist to be featured in their collection. The bohemian residence became an important meeting place for artists and political activists from Mexico and abroad.

She encouraged her students to treat her in an informal and non-hierarchical way and taught them to appreciate Mexican popular culture and folk art and to derive their subjects from the street. She had been very ill throughout the previous year and her right leg had been amputated at the knee, owing to gangrene.Back in Mexico City, Kahlo and Rivera moved into a new house in the wealthy neighborhood of San Ángel. During her slow recovery, Kahlo taught herself to paint, and she read frequently, studying the art of the Old Masters. She painted mostly still lifes, portraying fruit and flowers with political symbols such as flags or doves.

While the experience made her reclusive, [145] it made her Guillermo's favorite due to their shared experience of living with disability. In 1922, Kahlo was enrolled in the Preparatoria, one of Mexico's premier schools, where she was one of only thirty-five girls.In the same year, Kahlo joined a gang of students who shared similar political and intellectual views.

Due to her spinal problems, she wore twenty-eight separate supportive corsets, varying from steel and leather to plaster, between 1940 and 1954. To explore these questions through her art, Kahlo developed a complex iconography, extensively employing pre-Columbian and Christian symbols and mythology in her paintings.Frida, meanwhile, was often immobilized in a cast in her bed, or confined to a hospital room, either anticipating a surgery or recovering from one. In one of her early paintings, Self-Portrait Wearing a Velvet Dress (1926), Kahlo painted a regal waist-length portrait of herself against a dark background with roiling stylized waves. While he had been unfaithful to her before, he now embarked on an affair with her younger sister Cristina, which deeply hurt Kahlo's feelings. Inspired by the country's popular culture, she employed a naïve folk art style to explore questions of identity, postcolonialism, gender, class, and race in Mexican society.