Just to sharing to others that see this topic, this was the code added to the functions.php of the child theme
if (!function_exists('sf_custom_content_functions_child')) {
function sf_custom_content_functions_child() {
include_once(STYLESHEETPATH . '/includes/sf-portfolio.php');
}
add_action('init', 'sf_custom_content_functions_child', 0);
}
-Rui