Parent Permalinks

Im currently using code to call the parent page title as a link above my sidebar menu on content pages, as well as a ‘back to parent’ button at the bottom.

Code for Parent Page Title Link in functions.php:

function my_page_ancestor() {
    global $post;
    if( !is_front_page() ) {
        $parents = get_post_ancestors( $post );
        $top_parent_link = get_permalink( end($parents) );
        echo '<a href="' . $top_parent_link . '"><span class="pageAncestor">' . get_the_title( end($parents) ) . '</span></a>';
    }
}

Code used in template:

<?php my_page_ancestor();?>

Code used to display back to parent link on page (code placed in template file):

<?php if($post->post_parent) {
	$parent_link = get_permalink($post->post_parent); ?>
<a href="<?php echo $parent_link; ?>">&#8592 Go back a step</a>

My problem is, when I click to a child of a child of the parent post, both links disappear. Eg, when clicked on ‘Parent’ and ‘Child 1’ bellow everything works fine. When I click on ‘Child 2’, the links are gone.

IE

Parent
– child 1
– – child 2