Gorgeous red hair, beautiful lighting, the DOF really is exceptional with the tall grasses behind her. Only complaint (don't get me wrong Berlin is a wonderful city) the lettering on the tank top is distracting in this nice portrait.
Other than her skin looking a bit pale (colour cast maybe), I like her expression and stance. Your background is a little bright too. Her hair looks fantastic the way it is set and the angle of the light hitting it makes it look very nice. The background is very good as is the overall composition.
Very nice image, good focus, environmentally, the jury is still out... 7.. may bump later,The jury is back in, and although this is a good photo,and the subject has been photographed very well, do not believe it fully fits the wording of the challenge, of the subject being in there own invironment,this looks to be more of a shot in a park, because of the quality of the image will not alter original vote.