Final Stage: Shading added to sides of face and chin. This was done by taking a copy of the face shape and using "strokes to path" option. This creates a "tram line" inner shape that follows the original shape. The nodes on the "tram line" can be moved to create the shade which can be then overlay the original face shape. Remember to use the filling tool to make the black transparent so that the face colour underneath shows through, but darker.
Now we have BabyBoy and BabyGirl lets introduce them. BabyGirl can be flipped left to right so that she faces BabyBoy. That wasn't much work so I added the blocks "just for fun".