In order to enhance a rather dull flat image which is good for post processing, I quickly do some level adjustments, before I show it to the customer.
Here is the image after the quick and dirty level adjustments:

Here is a crop from the face:

Here is the crop as a photoshop file for you to download and see what I did with the image:
http://www.bloomi.de/images/girlwithdogcrop.psd