What is the ruling on money taken from female students as a fine, and how is it to be returned to those entitled to it, and what if they have left the place?

It is not permissible for a teacher to punish a talking female student by making her pay a sum of money, due to the hadith: "The wealth of a Muslim person is not lawful except with his willing consent," and the statement of Ibn Hazm: "No one's wealth is lawful without a text or a certain consensus, and it is not permissible for anyone to impose a fine that was not enjoined by the Qur'an or the Messenger of Allah, peace be upon him." And since it is difficult to identify the students, she should give the money as charity intending the reward for its owner.