WPquery + add row every nth element - wordpress

Question

So the case if following - i've got a wpquery like on the code below.
<section class="row service_block_row bgf" id="page-<?php the_ID(); ?>">
<div class="container">
<div class="row">
<div class="col-sm-12">
<?php
$args = array(
'post_type' => 'page',
'posts_per_page' => -1,
'post_parent' => $post->ID,
'order' => 'ASC',
'orderby' => 'menu_order'
);
$parent = new WP_Query( $args );
if ( $parent->have_posts() ) : ?>
<?php while ( $parent->have_posts() ) : $parent->the_post(); ?>
<div class="row">
<div class="col-sm-12 col-lg-3">
<h1><?php the_title(); ?></h1>
</div>
</div>
<?php endwhile; ?>
<?php endif; wp_reset_query(); ?>
</div>
</div>
</div>
</section>
What I would like to achieve is to have the loop working like that:
<ROW>
<COL-LG-3>
<COL-LG-3>
<COL-LG-3>
<COL-LG-3>
</ROW>
SO in fact what i would lke to achieve is to have 4 elements inside row without creating different loops. I know i should use some counter but i have no clue how;/
thanks

Answer 1

Add new row after 4 cols
<section class="row service_block_row bgf" id="page-<?php the_ID(); ?>">
<div class="container">
<div class="row">
<div class="col-sm-12">
<?php
$args = array(
'post_type' => 'page',
'posts_per_page' => -1,
'post_parent' => $post->ID,
'order' => 'ASC',
'orderby' => 'menu_order'
);
$parent = new WP_Query( $args );
if ( $parent->have_posts() ) :
$count=0;
?>
<div class="row">
<?php while ( $parent->have_posts() ) : $parent->the_post();
$count++;
?>
<div class="col-sm-12 col-lg-3">
<h1><?php the_title(); ?></h1>
</div>
<?php
if($count%4==0)
{
echo '</div><div class="row">';
}
endwhile; ?>
</div>
<?php endif; ?>
<?php wp_reset_query(); ?>
</div>
</div>
</div>