Oh, good; so they are both at an appropriate age to ask for a narration.
And you can guide their narration by asking what they know about different aspects of the subject. For example, if you are doing Lesson 1 on Cleanliness (p. 14), you might ask “How would you define Cleanliness?” Listen to their answers, let them know what you like about those answers, then share the definition in the book and ask, “What do you think about that definition?” Again, listen to their answers.
Next it says to share any goals you have for that habit. So you might say that you thought of one way you all could work on Cleanliness this month and share that one application, then ask if they have any other ideas on ways that you could all work on Cleanliness. Perhaps ask why that application is important to them.
Finish up by reading the Bible verse and briefly touching on those final two sentences. If you have any examples or stories of cleanliness from your past that illustrates those truths, you might share that story. But be careful not to launch into a lecture or sermon. You want to share a seed of an idea, and then give it space and time to grow in their hearts.
In a couple of days or a week, you can do the next lesson and share one more seed of an idea.
Just keep in mind that your goal is not to demonstrate how much you know; your goal is to plant seeds of ideas and let your children ponder on those seeds and then demonstrate what they have learned. Open-ended questions (and an open and listening heart) will help in that process.