I needed to make a loop to get a list of pages and show the children and grandchildren for each page, as well as truncated content of each result. I couldn’t find this as a question anywhere and this is what I came up with. This works as is, so I wanted to document what I’ve found and ask for help cleaning it up for others if they needed similar.

<?php 
$args2 = array(
    //'cat' => 7, 
    'post_type' => 'page' , 
    'post_status' => 'publish', 
    'posts_per_page' => 2,
    'post__in' => array( 10, 1987) ,
    );
$the_query1 = new WP_Query( $args2 );
$title_content = "50";
$content_length2 = "140";
?>

<? if ( $the_query1->have_posts() ) :  ?>
<!-- pagination here --><!-- the loop -->
<?php while ( $the_query1->have_posts() ) : $the_query1->the_post(); ?>

<div class="row">

    <div class="medium-9 small-9 columns article-thumb">

        <a href="<?php the_permalink();?>"><?php echo truncate(strip_tags(get_the_title()),$title_content); ?></a> 

        <p class="p-16x"><?php echo truncate(strip_tags(get_the_content()),$content_length2);?>...</p>

        <?php $children = new WP_Query( array('post_type' => 'page', 'post_parent' => get_the_ID() )); ?>

        <?php if ( $children->have_posts() ) : ?>

        <ul class="post-children">

            <?php while ( $children->have_posts() ) : $children->the_post(); ?>

                <li><?php the_title('<h3 class="child1">', '</h3>'); 

                 echo truncate(strip_tags(get_the_content()),$content_length2);?>

                    <?php $gchildren = new WP_Query( array('post_type' => 'page', 'post_parent' => get_the_ID() )); ?>

                    <?php if ( $gchildren->have_posts() ) : ?>

                    <ul class="post-gchildren">

                        <?php while ( $gchildren->have_posts() ) : $gchildren->the_post(); ?>

                            <li><?php the_title('<h4>', '</h4>');

                              echo truncate(strip_tags(get_the_content()),$content_length2);?>

                            </li>

                        <?php endwhile; ?>

                    </ul>

                    <?php endif; ?>

                </li>

            <?php endwhile; ?>

        </ul>

        <?php endif; ?>

    </div>

</div>  

<?php endwhile; ?>
<!-- end of the loop -->
<?php wp_reset_postdata(); ?>

<?php else : ?>

<p><?php esc_html_e( 'Sorry, no posts matched your criteria.' ); ?></p>

<?php endif; ?>