Does a teacher of the Quran bear sin if the girls she teaches are not adhering to the Hijaab?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

 A teacher of the Quran has to observe her duty: to advise, command what is good and forbid what is wrong, and to warn her students against not wearing the Hijab and to explain the danger to them.

If her students obey her, then this is what is required, but if they reject her advice, then she is not sinful because she has fulfilled her duty of advising and warning them against the wrongdoing.

Allaah Knows best.