Final answer:
Florence Kelley was the Progressive reformer who championed and helped pass legislation in Illinois that prohibited child labor and limited women's working hours. She was instrumental as a labor reform advocate and became the state's first female factory inspector.
Step-by-step explanation:
One Progressive reformer who won passage of the law in Illinois that prohibited child labor and limited women's working hours was Florence Kelley. Kelley was a staunch advocate for labor reform and played a pivotal role in lobbying for legislation that aimed to protect women and children in the workplace. She investigated sweatshops, became the first female factory inspector in Illinois, and successfully pressed for the passage of laws that not only prohibited child labor but also regulated working hours for women and sweatshop conditions. Moreover, her commitment to labor reform didn't stop there; frustrated by a lack of legal enforcement, Kelley pursued a law degree to ensure that these protective laws would be properly observed.