1 Introduction Estimating the global size of the population of female sex workers (FSWs) is extremely difficult, if not impossible (Sabin et al. 2016). Estimating the number of FSWs engaged in a particular type of sex work (street and brothel based1) and who are also mothers, with any degree of certainty, is even more daunting. The sex market operates along a continuum of organization, complexity, and varying levels of vulnerability and exploitation (Kjellgren 2024).