Display Parent and Child Page Titles on Page

parent-child-titles.php

//* Display Parent and Child Page Titles on Page
add_filter( 'genesis_post_title_output', 'lit_post_title_output', 15 );
function lit_post_title_output( $title ) {
 
    global $post;
	
    if ( is_page() && $post->post_parent > 0 ) {
	
        $parent_title = get_the_title( $post->post_parent );
        $page_title = get_the_title();
        $title = sprintf( '<h1 class="parent-title">%s</h1><h2 class="entry-title">%s</h2>', $parent_title, $page_title );
    }
    return $title;
}