There is a very easy solution to your problem. Just add a capability to the particular role of this user, through the Wp_Role class. WordPress has this feature of Submitting for Review active for authors and contributor by default, but, if you want to use pages, you have to give them the edit_pages capability, but not the publish_pages one, so that they can Add new pages without being able to Publish them. This will activate the Submit for review button instead of the Publish one.
Think of something like this:
function my_authors_can_help_with_pages() {
$user_role = get_role( 'author' );
$user_role->add_cap( 'edit_pages' );
}
Then hook somewhere, whether in a plugin or functions.php, for example:
add_action('init', 'my_authors_can_help_with_pages');
Ideally, use an hook that is run the least amount of times, like after_setup_theme if its in your theme. Once you add the capability you don’t need to add it multiple times: it doesn’t do much bad, not it is a real performance issue, I guess it is more of an issue of elegance.