My teenager is so stressed about exams that she cannot sleep. How do I help her?

Exam stress that affects sleep and appetite is a sign she needs support, not extra pressure. Lighten the load by telling her you love her regardless of her marks, and stay away from comparisons with other children. Discuss a revision timetable broken into small parts, with enough rest and sleep. Remind her to make du'a and trust in Allah after making an effort, because Allah “does not burden a soul beyond what it can bear” (Surah al-Baqarah 2:286). Make sure she eats and moves, because a healthy body calms the mind. If the anxiety persists or becomes extreme, see a doctor or the school counsellor. More information at mental health.