Napawn Somsak took to the stage in her school uniform, her hair in pigtails, to denounce sexism in Thai society and question the treatment of a royal princess — an act unthinkable before the protests that have roiled the country in recent months.

Before a cheering crowd of more than 2,000 people in the northern province of Chiang Mai, the 18-year-old demanded to know why women are paid less than men and cannot be ordained into the influential Buddhist monkhood.

Somsak is among the large numbers of young Thai women calling publicly for change, emboldened by widespread demonstrations to demand the departure of Prime Minister Prayut Chan-ocha and reforms to the powerful monarchy.