wordpress shortcode to make featured image gallery from pages

what I was looking to do here is to have a shortcode that shortcode that shows the featured images of a range of Post or Pages.

One issue I've had to overcome here is that I couldn't get get_the_post_thumbnail to work for me.

Here's the code I've written which you'll need to put in your templates function.php

function page_featured_images_ofparent() {
$postid = get_the_ID();
$children = get_children($postid);

foreach ($children as $child):
// print_r($child);
 //echo "

"; 
$child_id = $child->ID;
$URL = $child->guid;
$title = $child->post_title;
// echo "Child Id = $child_id 
"; 
if(has_post_thumbnail( $child_id )):
$image = wp_get_attachment_image_src( get_post_thumbnail_id( $child_id ), 'thumbnail' );  // 'single-post-thumbnail'
 $image_url = $image[0];
 echo '

 '.$title.'
';
endif;
 endforeach;
return;
}
add_shortcode ('page-feat-img-childs', 'page_featured_images_ofparent');

and you can use the code

[page-feat-img-childs]

Put this wordpress shortcode on any of your posts or pages and it will show all the featured images of any child post or blogs.