[Related Children] get the related children and exclude current post #wordpress

addons.php

// count for wpquery, goes here

$the_query = new WP_Query( $args );
$count     = $the_query->found_posts;
// then inside of the content
		if ( $count > 2 ) {
				echo '<div id="np-slider-three" class="np-slider">';
			} else {
				echo '<div class="grid-x grid-margin-x medium-up-3">';
			};

related-children.php

<?php

/**
 * display related children using WP Query setting the parent as the parent of the current page, and excluding the current page from results.
 */

$title = get_field('other_children_headline');

?>

<section class="related-children">
	<div class="grid-container">

		<?php
		$currentID  = get_the_ID();
		$current    = $post->ID;
		$postParent = $post->post_parent;
		$args       = array(
			'post_type'      => 'page',
			'posts_per_page' => - 1, //gets all of them
			'post_parent'    => $postParent,
			'post__not_in'   => array( $currentID ),
			'order'          => 'ASC',
			'orderby'        => 'menu_order'
		);

		$the_query = new WP_Query( $args );

		// The Loop
		if ( $the_query->have_posts() ) {

			if ($title) {
				echo'<header class="related-children__header">';
				echo '<h2>' . $title . '</h2>';
				echo '</header>';

			}

			echo '<div class="grid-x grid-margin-x medium-up-3">';

			while ( $the_query->have_posts() ) {
				$the_query->the_post();

				$img         = get_field( 'teaser_image' );
				$teaser      = get_field( 'teaser_body_copy' );
				$teaserTitle = get_the_title();
				$cta         = get_field( 'teaser_button_text' );

				if ( $img ) {
					$imgUrl = $img['url'];
				} else {
					$imgUrl = '/wp-content/uploads/2018/10/Y-Axis-Milling.jpg';
				}
				?>

				<div class="box-with-slide-up-wrap cell">
					<a href="<?php echo get_permalink(); ?>">
						<div class="box-with-slide-up"
						     style="background:url(<?php echo $imgUrl ?>) no-repeat center; background-size: cover; ">
							<div class="box-with-slide-up__text">

								<h4 class="box-with-slide-up__title"><?= $teaserTitle ?></h4>
								<div class="hidden"><?= $teaser ?></div>
								<div class="button"><?= $cta?> <span class="fas fa-chevron-right"></span></div>

							</div>
						</div>

					</a>
				</div>
      
				<?php
			}
			echo ' </div>';

			wp_reset_postdata();
		} else {

		}
		?>
	</div>
</section>