Kmccanta, I'm a parent, and I've gone through much of the same ordeal. So far, here's what I do to chase my 4 month old:
1) Decouple the shutter from the autofocus. If the k100d allows this, then disable "AF when press halfway" and enable "AF button function" (custom menu). Use your right thumb to autofocus with the AF button and fire the shutter with your right index finger. Few things angered me more than waiting for the AF to quit hunting while I held down the shutter button, only to watch the moment slip away.
2) Often, but not always, I set the AF dial to "select" and move the red dot to where I think my daughter will be. This eliminates the "focus and recompose" step.
3) I always aim for the leading eye of the subject, using the red dot as my "sight". I NEVER use the "auto" (green) position on the AF dial. When shooting guns, as well as photographs, the axiom "aim small, miss small" will serve you well.
Please let us know if this helps.
Here's a pseudo action shot: k10d, 43mm f1.9 ltd: f2.5, 1/15 sec, ISO 400