In 1919, Schneiders-Howard became an employee on a contingency basis for the sanitation department. Within two years, she was promoted to temporary sanitation inspector. An ordinance was passed, in 1923, to enforce hookworm controls and appoint sanitary inspectors who had been trained by the Rockefeller foundation. The following year, Schneiders-Howard was made Chief Sanitation Inspector, becoming the highest ranking woman employee in the colonial administration. Her duties included inspecting latrines, rubbish and weeds in Paramaribo and the surrounding plantations and settlements. Imposing fines for failure to build latrines or keep them clean, Schneiders-Howard worked around ten hours per day inspecting 150 plots of land. Dismissed for her outspoken disagreement with her superiors and officials in 1930, she was reinstated in 1933. Not content with pressing for financial support from officials to deal with public health issues and construction of the drainage and sewage system, Schneiders-Howard saw rainwater collection as a breeding ground for mosquitoes, which carried the yellow fever virus, among other diseases. She was instrumental in bringing a water supply system to Paramaribo in 1933 and simultaneously blocking wells and removing all open collection vessels. In 1937, she was again fired from her position for insubordination to her superiors. Though not a feminist nor a suffragist who fought for women's right to vote, Schneiders-Howard was quick to take advantage of the opportunity when women were first allowed to run for office in 1936. Asians, workers and women did not have enfranchisement, but when she ran and was elected in 1938, Schneiders-Howard became the first woman to serve in the Estates of Suriname, as the legislature was called at that time. Her areas of interest, while in office, were on the cost of living, wages and working conditions; public health, clean water and sanitation; small agriculture; and road conditions. She staunchly supported Dutch rule, was not in favor of changing governance from the colonial system, and was fervently against Nazism. As she had in her previous civil service position, Schneiders-Howard often clashed with her male colleagues, personally attacking them and their positions. In one case, she falsely accused a prominent businessman of burning a Dutch flag. These types of behaviors made her a controversial figure, praised by some for her well-informed, trustworthy, willingness to work and belittled by others for her failure to behave as a respectable woman. After one term, she was not returned to parliament, though she ran again in 1942, 1943, and 1946.