Is selling ready-made presentations to students, knowing that they can prepare them themselves, forbidden?

There is no objection to a woman creating presentations with her voice, provided that her manner of delivery does not involve softness in speech. It is permissible to do so on behalf of students if the school or college does not prohibit it and there is no deception involved. However, if it is prohibited, or if preparing the presentation is an assessment for the students to gauge their level, then it is not permissible and is considered forbidden deception.