add JS to multiple plugin admin pages

It would be easiest to run some conditional logic on $parent_file inside a callback hooked onto admin_print_scripts, and would go a little something like this..

add_action( 'admin_print_scripts', 'possibly_enqueue_script' );
function possibly_enqueue_script() {
    global $parent_file;
    if( 'my-slug' == $parent_file )
        wp_enqueue_script(  ... your enqueue args .. );
}

You’ll need to replace my-slug with the handle of your parent page, it’s the fourth parameter in add_menu_page…

The script will then enqueue for both the parent page and any of it’s children pages..

Hope that helps…