As I was trained in RBT. A suggestion is when a child is playing with their toys play with them so when you tell them let’s read the book afterward they tend to follow it. When a kid isn’t paying attention to you reading that means he/she isn’t interested and whatever they are doing is what they would wanna do. So for child’s development I’d say stay connected to child through what they wanna do. Then you can read the books to them and tell them to read it with you.