gistfile1.php

<?php
/**
 * Implements hook_form_alter().
 * todo: change weight to something dynamic. IF we reorder anything it will be out of place.
 */
function add_teach_embed_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id === 'school_node_form') {
    $form['add_teacher'] = array(
      '#type' => 'fieldset',
      '#title' => t('Add Teachers'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#weight' => '12',
    );
    $form['add_teacher']['add_teacher_form'] = drupal_get_form('add_teach_embed_form');
  }
}