How might you determine if there is a connection between the mother’s new job and her child’s illness?

A woman delivers a healthy baby just prior to starting a new job at a small manufacturing plant. Within a few months after she starts work at her new job, her infant appears sickly and is hospitalized. The woman discusses her newborn’s condition with her co-workers and finds an unsettling similarity to events that led up to the illness of another female coworker’s child. First, how might you determine if there is a connection between the mother’s new job and her child’s illness? Speculate what factors you might have to address and how would you test to prove that there was a connection. Would the woman have a case if it were taken to court? Why, or why not?