It's a candid all right. Not terribly interesting though. If the child was walking into the frame it might help. Also, I'm confused by what the selective desat is supposed to add to the shot. It does draw attention to the subject which is walking away from the camera into an area you can't see because the umbrella blocks the background...
TC
The post-processing to B/W in the surround is so evident here that it made the photo feel less candid to me. Incidentally, in doing such selective desaturation, pay carefull ateention to the transitions. sme grass to her left and udner the unbrella is still green, and this hurts.
Even had this been all color or all B/W, it is less succesful than many as a candid to me because there's no real emotional content; hands and faces carry most of the weight for that, and neither is evifdent in this image. This is a personal aesthetic bias; others may disagree.