Vslider – header image not centered. Help!

Hello. I’m new to html coding and I’m having an issue with my vslider images not being centered on my home page. I created a child directory of the twentyeleven theme and moved:

<?php
      vslider('header');
           ?>
      <?php

right after :

<?php endif; // end check for removed header image ?>

but as you can see (https://drandersenobgyn.com) the image is far aligned to the right . I have modified the theme by bringing the menu bar above the header image and would like to keep it that way.

Any pointers would be much appreciated!

Thanks in advance!