Since April, dozens of female soldiers have become part of the security services that monitor pilgrims in Mecca and Medina, the birth places of Islam.
Dressed in a military khaki uniform, with a hip-length jacket, loose trousers and a black beret over a veil covering her hair, Mona spends her shifts roaming in the Grand Mosque in Mecca.
"I am following the steps of my late father to complete his journey, standing here at the Grand mosque in Mecca, the holiest place. To serve the worshipers is a very noble and honorable task," said Mona, who declined to give her family name.
Saudi crown prince Mohammed bin Salman has pushed through social and economic reforms as part of plans to modernize the conservative Muslim kingdom and attract foreign investment under a diversification drive.
But the reform plan has been accompanied by a crackdown on dissent, including on women's rights activists.
Samar, another soldier watching pilgrims near the Kaaba, the holy cube-shaped structure that Muslims believe was built by Abraham, said she was encouraged by her family to join the military, after psychology studies.
"This is a huge accomplishment for us and it is the biggest pride to be in the service of religion, the country and the guests of God, the most merciful," she said.