If you have seen some blogs where a number of comments in that particular post is displayed right next to the post title in a bubble, then envy no more because this article explains how you can do it. You will just need to open your functions.php in your child theme (make sure to have a backup of this file in case something happens). Once you have opened the file, you need to create a new function called, childtheme_override_postheader_posttitle(). This function will override the parent themes postheader_posttitle function, which is used to display the title for each post.
Read more about it in this link: http://www.cheesetoast.co.uk/comments-bubble-for-wordpress-titles/