Loop for Child Pages.

childpage-loop.php

<!-- Display all child pages -->

  <?
$child_pages = $wpdb->get_results("SELECT * FROM $wpdb->posts WHERE post_parent = ".$post->ID." AND post_type = 'page' ORDER BY menu_order", 'OBJECT');

if ( $child_pages ) :
    foreach ( $child_pages as $pageChild ) :
        setup_postdata( $pageChild );
        $thumbnail = get_the_post_thumbnail($pageChild->ID, 'thumbnail');
        if($thumbnail == "") continue; // Skip pages without a thumbnail
?>
        <div class="child-thumb">
          <a href="<?= get_permalink($pageChild->ID) ?>" rel="bookmark" title="<?= $pageChild->post_title ?>">
            <?= $pageChild->post_title ?><br /><?= $thumbnail ?>
          </a>
		  <div style="width:70%;float:right;">
          <?php the_excerpt(); ?>
		  </div>
        </div><br /><br />
<?
    endforeach;
endif;
?>