What is the ruling on hitting female students, whether it is to discipline them or make them work harder?
It is good for the teacher to be kind and gentle towards young and old, but if the situation calls for discipline or a (light) smack that is not severe, that is permissible. It is the habit of the foolish to behave badly and not show any respect, so there is a need for strictness and strength that is more effective than kindness and gentleness. End quote.
Shaykh ‘Abd al-Rahmaan ibn Jibreen (may Allaah preserve him)
Fataawa ‘Ulama’ al-Balad al-Haraam, p. 399
See also the answer to question number 50022
And Allaah knows best.