page-content-from-child-templates.php

<?php 

$args = array(
	// Get children of current page
	'post_parent' => $post->ID,
	'post_type' => 'page',
);

$query = new WP_Query($args);

if ( $query->have_posts() ) : while ( $query->have_posts() ) : $query->the_post();
			
	$template = get_post_meta( $post->ID, '_wp_page_template', true );

	// Template must have 1 dash. EG: "template-name.php"
	$template = pathinfo($template);
	$template_parts = explode('-', $template['filename']);
	
	// use first 2 keys in array of $template_parts
	get_template_part( $template_parts[0], $template_parts[1] );

endwhile; endif; ?>