The beauty is in the eyes of the beholder. Not very fare of you to say that it is cheese just b/c you don't like it.
As it is right now, as much work as folks put in this image, she blends in with the foreground, sadly enough. Thus adding or subtracting color is one few ways to have pop out. Not home right now to try, but I'll see maybe I can play with this image in Vivieza
Whenever I see selective coloring, I can't help but think of those "1 hour photo studios" you see in the mall. They always try to sell the selective color prints. To me, selective coloring is very tacky, unless it's done right. In my eyes, this is NOT the type of shot to selective color. Try it if you like, but I really don't think it would add anything to this shot.
And actually, I think this might be a good candidate for a re-take, if it's possible. I might put her in something a bit darker, or with color in it, just to contrast with the edge of the pool. Would make her stand out a lot better, without resorting to tacky photoshop tricks.