It could well even out when she showers in the morning as there is a chance it's just the guidecolour that's rubbed off on that area? Looking at the photo though, it looks as if her skin is rather dry, or did she have remnants of an old tan left on her skin? If so, that could explain why it looks patchy. To be honest, my own neck area usually looks awful before I wash the guide colour off, but looks fine afterwards so probably best to wait until she's rinsed off to see if there's still a problem. If there is still a pale patch, maybe try applying a small amount of the tan on a tanning mit just to that area?
