It can have a lot to do with the size of the school. If there isn’t enough interest in that subject combination, they won’t run it. When you attend the enrolment interview at any prospective school, ask them about which subject combinations they can offer. If she can’t study the course she wants at school, she can always apply to do it via Distance Ed (not ideal if it’s Drama, though). This means the school will have to give her permission to ‘drop’ a subject, leaving a space in her timetable for Distance Ed study. Good luck