How to get children categories name

WORDPRESS VERSION: 2.7.1

Hi,

I am trying to get the name of child category whose article get’s printed as the latest one from the Root category. I have a hierarchy of categories in my site e.g.

* ROOT
|- child 1
|- child 2
|- child 3

With the following code, WP prints out “Root” category name with an article from one of the children depending which is the latest one:

<?php query_posts("showposts=1&cat=$category");
	    $wp_query->is_category = false;
		$wp_query->is_archive = false;
		$wp_query->is_home = true;
		 ?>
      <h3><a href="<?php echo get_category_link($category);?>">
        <?php
	// name of each category gets printed
	  single_cat_title(); ?>
        </a></h3>
      <?php while (have_posts()) : the_post(); ?>
      <?php

The function single_cat_title(); prints out the Root category name and I would like to replace it with the name of the child category.

Thanks for your help!

Omer