Very nice first portrait! Great use of a single light source. Your bold use of color is also very well done.
I would suggest you soften the edges, and pay closer attention to the color of the light. For example, I think the brightest area should be near the forehead and filter down, not under the brow bone as you've indicated. Although I know the baby has pretty flushed cheeks, you can ease up on that intensity where the light is falling. Check out Karin's work for good examples of that color adjustment
