Kirby doesn't output any markup, you have total control to over it :D The API for querying content is very powerful.
<?php $latest = page('blog')->children()->visible()->limit(6); ?>
<div class="widget">
<?php foreach($latest as $post) : ?>
<a href="<?= $post->url()?>"><h2><?= $post->title()->html() ?></h2></a>
<?php endforeach ?>
</div>
Instead of fetching the post on the template, you could use a controller and just pass the $latest variable to the template.