Professional photographers consider selective coloring to be passe, like the cheesy "couple in a brandy snifter" portrait that some people thought was elegant or classy. You'll still find plenty of photographers that do selective coloring, because their paying customers ask for it, but it's not something that many are proud to share with their peers. It may be snobbish to put down selective coloring, but the biggest problem that I have with it is that 99.9% of the time it's done poorly. In most instances, the area in color is NOT the most important part of the image, and it usually distracts the eye away from what should be most important. For instance, in portraits the focus of attention should usually be on the subject's eyes and face. However, selective focus images invariably have the dress or flowers in color, disrupting the heirarchy of importance within the image. Using the images in the original post as an example, the message that each image transmits to the viewer is that the children are unimportant background, the most important thing is this sole flower, or Tinkerbell. I dont' think that's what the photographer had in mind whe she took the pictures, but that's what happened after selective coloring was applied.
Not every image is a good candidate for effective selective coloring. Try taking a close-up of your daughter, then applying selective coloring to just her eyes (maybe a little on her lips). Not too much, just a little color.
Good images simplify, focus attention on the subject, and eliminate anything that distracts attention away from the subject.