One possible explanation is what we call 'splinter skills' - when a child likes doing something so much, such as art and writing, she focuses on that and ignores other types of play.
Of course, there are so many different variables with each child, it's difficult to pinpoint why she is developing in this way. But that's not fine motor skill - not yet. Each day, you'll see more and more deliberate hand and finger movements. Over time, early reflexes integrate and the pincer grip kicks in, allowing him to use his forefinger and thumb together in unison. Young hands begin with simple, reflexive, whole-hand grasping. Now, that doesn't mean that your child's hands aren't active as he's growing. So you see, on the developmental totem pole, the hands come last. This order of priority, established by the brain, insures that the large muscles necessary for coordination and locomotion (getting from here to there) are well organized and in control, before taking on the complex mastery of the more than 60 combined muscles in the hands (let alone the dozens of bones, hundreds of ligaments and tendons, etc., etc.)
Children's muscle control and coordination is developed in a natural, orderly way - from the top down and from the inside out - starting at the head and working towards the toes while building out from the torso to the limbs.
