Final answer:
A school nurse's main focus in the early twentieth century would have been to provide medical treatment to ensure children could attend and participate in school effectively.
Step-by-step explanation:
If a nurse worked in a school setting during the early twentieth century, the focus of this nurse's practice would have likely been providing medical treatment to enable children to return to school. During this time, public health and school nursing began to emerge as important components of the education system. Nurses played a critical role in addressing health issues that could lead to absenteeism, such as managing communicable diseases like tuberculosis and influenza that were common in school settings. Their presence aimed to reduce barriers to student attendance and learning by ensuring children were healthy enough to participate in school.