Javascript that will execute on only child pages of a specific parent

Semi-new to WordPress, so apologies is this is an obvious question!

I’m trying to execute some JavaScript on a WordPress site, but only on the child pages of a specific parent page – so, I have example.com/books, and I want the script to run on example.com/books/foo, example.com/books/bar, example.com/books/wee, and so forth. I don’t want it to run on example.com/books.

I know that I could just add in the script on each individual page, but I have other people editing the site who may add new book child pages, and they will not feel comfortable adding in Javascript.

Any solutions?

You don’t quite cover how far you got and if you are familiar with basic of WP enqueue process.

Focusing on parent part I the basic code would go like this:

add_action( 'wp_enqueue_scripts', function () {

    if ( is_page() && in_array( $book_page_id, get_post_ancestors( get_the_id() ) ) ) {

        // enqueue stuff
    }
} );

In your examples you only have one level and might have worked to just check post_parent of current post, but checking for ancestors is more thorough for more nested cases.