Has this ever happened to you? You watch your child intensely practicing a new movement. The struggle, the concentration, the determined grunts and muffled noises of effort. Nearly...Nearly...Almost... But not quite. They don't manage to stay in tummy time. They don't roll. They don't push up. They don't take that long-awaited first step. And somewhere in the back of your mind, a voice starts whispering: They should have done this a month ago. My friend's baby rolled at three