They also engaged in philanthropic activities and donated a hospital to their hometown of San Miguel. De León was widowed in 1934. She moved her family to Manila, took charge of the family business, and refocused it towards real estate. It was said that the business soared to new heights when she took full control after her husband's death. She would also become the first woman appointed to the board of directors of a government corporation when she was named by President Manuel Quezon to the board of the National Rice and Corn Corporation. In the 1950s, De León would be among the organizing shareholders of Republic Cement Corporation, which soon became among the leading cement producers in the country. Filipino film industry. She agreed, and in 1938, her family, along with the Villongco and Navoa families, contributed capital to establish a film studio. The company was named LVN Pictures, the name taken from the respective initials of the three founding families. Apart from de Leon, the two other principal founding partners of LVN Pictures were Carmen Villongco and Eleuterio Navoa Sr.  LVN broke into the Philippine film industry with the successful release of its first feature, Carlos Vander Tolosa's musical "Giliw Ko", released in 1939. De León was elected president of LVN Pictures in 1940, and she eventually bought out the shares of her other partners, gaining full control over the studio. "Giliw Ko" was followed with another successful film, Manuel Conde's "Ibong Adarna" (1941), which featured the first color sequence in a Filipino film and was the first local film to earn more than a million pesos. However, LVN Pictures was forced to close shop upon the Japanese invasion of the Philippines in December 1941. It resumed operations after the Liberation of Manila in 1945, and produced the first post-war Filipino movie, "Orasang Ginto" (1946). In 1949, LVN produced the first full-color Filipino feature film, "Batalyon XIII". Dissatisfied by the color-processing of that film, De León bought her own color laboratory for LVN. LVN Pictures saw the peak of its success in the decade following the war, hosting a stable of the most prominent film stars who had joined its studios such as Rogelio de la Rosa. In addition to producing commercially successful films, LVN also featured critically acclaimed prestige films such as Lamberto Avellana's "Anak Dalita" (1956), which was named Best Film at the 1956 Asia-Pacific Film Festival.