<?php
                    if($post->post_parent)
                    $children = wp_list_pages(\"title_li=&child_of=\".$post->post_parent.\"&echo=0\");
                    else
                    $children = wp_list_pages(\"title_li=&child_of=\".$post->ID.\"&echo=0\");
                    if ($children) { ?>
                    <div class=\"summer_side\">
                    <h3 class=\"child-nav\">
<?php
$parent_title = get_the_title($post->post_parent);
echo $parent_title;
?>
                    </h3>
                    <ul>
                    <?php echo $children; ?>
                    </ul>

$children = wp_list_pages(\"depth=1&title_li=&child_of=\".$post->post_parent.\"&echo=0\");
                    else
                    $children = wp_list_pages(\"depth=1&title_li=&child_of=\".$post->ID.\"&echo=0\");