No, there is no way to duplicate 2 apps that point to the same sheet and have them both point to the same duplicated sheet. You would have to recreate at least one of the apps, or like I posted earlier in this thread, create the Admin/Student functionality in both apps so you can duplicate it with a new sheet, and duplicate it again with the same sheet and then manually hide admin only and student only tabs/components in their respective apps.
An alternative is to build the admin and student functionality into one app, which it looks like you have explored in a different post from today.
One question I have is, why build separate apps for each class when you could really do the same thing with a single or double (admin/student) apps and only show whats relevant to that instructor/student? i understand if you are sharing a template with others, or you have a different client, but it sounds like you would be administering all of this withing the same school.