There is nothing un child friendly about the watch faces. Also a watch this expensive isn't really good for a child to have anyways unless they are old enough to have a phone and won't break it easily.
If you really want a watch face that a child might like then you could use the endangered animals watch face which has little sketches of panda bears, turtles and other animals that a child might like.
Download Watchmaker by androidslide in the play store on your phone, you can build any watch face you want. I been using that app since the original moto360
