Play for a toy, or a stuffed animal, or a pet. Make the animal give instructions.
Every time a child learns a song, make a card (a different colour for each book) use these cards as review. For example you can say draw 2 book 1, 2 book 2, and 2 book 3 songs to play. After they play these songs put the cards into a “done” container. Eventually all the songs get played.
Have the child choose a goal on a review song.
When the child is working on a goal play a game where you ring a bell for the player to stop and check on themselves.
If a young player has a lot of things they are working on. For example, “bent thumb”, “scroll up”, “straight bow”, “chin on chinrest”, and “mouse hole in violin hand”. When all the cards are made the student can draw a goal card for each review piece. Work on that goal only for that song. (Remember to keep quiet about the other goals, they may not be able to focus on more than one thing at a time).
Limit yourself to a certain number of constructive (negative) comments a session. It might only be 2-3. All other comments will be positive.