I think we need some more information about the situation to give better advice. What is the actual level of the class? Speaking ability? Reading? Writing? Listening? Is the subject wide open? Are you expected to follow a schedule? Is it absolutely necessary to follow a book? Are you able to do longer projects?
If you need some one-off lessons, Film-English has a few good plans, but you will need to wade through to find age appropriate content.
- Task-based learning projects that can be used over two or three class times may be a good bet.
- Consider looking for material that is intended for native speaking classrooms.
- Do you have access to (leveled) English books? Make it into a reading and writing class. Reading, vocabulary, book reports (or presentations).
- Presentation skills class
- Is it possible to use a computer lab? Teach them how to make PowerPoint presentations.
Hopefully a few of those ideas give you some help.