I've gotten a bit more painting done on this. Can't wait to finish it up! Yesterday I worked on the figure in the black shirt, going over certain areas of her face, doing another entire layer on her hands and arm, and deepening the shadow on her belly. This is all helping her to fade into the background in the shadows, and then emerge from them in the light. Her belly will need more work, as right now the light area is pretty flat.
Included above is an image of the painting in black and white. These values will be adjusted to carry the eye through the painting in a specific pattern. My plan is to lower values on the belly of the standing figure, lower the contrast on the white shirt somewhat, and then lighten the flesh tones overall on the sitting figure. This should help the eye move around the whole painting, to both faces and both bellies, whereas at the moment the flow seems to stick at the sitting figure's face and shirt. Also, note how it doesn't make sense for the belly of the standing figure to receive more light than the belly of the sitting lady, since the sitting lady is closer to the light source. All these things will be corrected after I make the changes listed above.