Can't make ghusl in time

السلام عليكم ورحمة الله وبركاته

If someone found out their menses had stopped right before they were abt to leave to school and there was 30 min left for Dhur. They can't make ghusl in time and will probably miss the prayer because their school time ends late and making ghusl will make them miss the prayer.

What to do in this situation?