What should the student do if she becomes pure from menstruation during school hours and cannot perform ghusl until after the time for prayer has passed?

In this situation, it is permissible for female students to perform tayammum (definition) with earth instead of ghusl (definition) until the impediment is removed and they are able to perform ghusl. Then, they should perform ghusl for menstruation, because tayammum is legislated for a menstruating woman who has become pure but cannot perform ghusl due to lack of water, or fear of harm from using it due to illness or severe cold, or due to the impossibility of ghusl. This is based on the Almighty’s saying: (And if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and find no water, then seek clean earth and wipe over your faces and your hands [with it]).