WP Events Manager grandchild pages

gistfile1.php

/* /classes/em-permalinks.php starting at line 197 */
$child_posts = get_posts(array('post_type'=>'page', 'post_parent'=>$events_page->ID, 'numberposts'=>0));

foreach($child_posts as $child_post){

    $em_rules[$events_slug.$child_post->post_name.'/?$'] = 'index.php?page_id='.$child_post->ID; //single event booking form with slug

    /* [new stuff] */				
    //check if child page has children
    $grandchildren = get_pages('child_of='.$child_post->ID);
    if( count( $grandchildren ) != 0 ) { 
        foreach($grandchildren as $grandchild) {
            $em_rules[$events_slug.$child_post->post_name.'/'.$grandchild->post_name.'/?$'] = 'index.php?page_id='.$grandchild->ID;
        }
    }
    /* [/new stuff] */
}