Kids Don't Care What's In The Piano Book
Kids don't care what's in the piano book. What they care about is the manner of the teacher. If it has pictures, that is a pleasant plus for many younger kids. You could teach the texts of the most boring piano teacher of all time, Carl Czerny, and still get a positive reaction out of the child if you proceed with humor and care. If a piano lesson is a lecture, then the child will not respond very well.
Sweeten The Piano Lesson Process
Make it into a fun, hands-on demonstration of how to operate a great big machine. You will unfailingly get a good reaction. It isn't that kids don't like the meat of reading music in piano lessons. It's just that they need other things on their plate besides the red meat of musical notation.
Being kids, they prefer sugar. In moderate amounts, a little sweetness is enough to fuel their continuing interest. It's like getting a kid to eat vegetables. They usually won't eat them with minimal preparation, but are more interested if you dress it up, with sauces and such.
So you need to find a way to make the more difficult parts of the piano (reading music) more palatable. At least wait until the child has engaged themselves with the instrument enough to have built their own enthusiasm.
Pretend Reading Music Doesn't Exist
My approach is to pretend that reading music doesn't exist until the child has firmly grasped the physical sense of playing simple songs. This delay ensures that children survive the introduction of reading music. If you introduce reading music right away, the child may think that reading music is all there is to the piano.
This is a fatal misconception on the part of almost all piano teachers. Without this delay, 90% of all kids who try the piano simply quit, tired of the diet of difficulty. What matters is not what is on the page, but what is in the teacher.