Well, there is a blur tool in Photoshop that you might want to use (in my old version its icon is a drop), but if that really is part of Ankhor Wat in the background (which I think it is), I would not blur it out, even though your subject is the girl and the horse (very pretty girl, lovely expression, by the way!). To my mind it is blurred enough but still somewhat recognisable. And it might be a bit of a tough job blurring the background still further around all that curly hair! Ugh. No job that I would want to do...