If your child is a beginner learner, then you have found the simplest method to help them start speaking English fluently!
Your role is to encourage your child to actively engage with every lesson. Doing the hand gestures will help them to memorize all the new vocabulary; speaking and singing will improve their pronunciation and fluency.
You can also use the PDF translation of the lesson to explain to your child what is happening in the presentation scenes (Scenes 1, 3 and 7). This will help your child to understand the lesson.
Learning occurs when a child makes an effort to interact with the lesson. Therefore you should give praise when your child makes an effort to speak, do the gestures or sing along with Sam and Mel. The child's reward is their sense of accomplishment at succeeding to speak. Children can also earn Olympic medals as they move through the course completing the lessons.
If the child thinks they are ready for the next lesson, it is a good idea that they do the lesson in the parent's presence to show that they can achieve the following goals:
The child's performance does not have to be perfect before moving on to the next lesson. They can always come back to review and practice a lesson again in the future.