Shadows are essential in making this piece read well. With such a limited palette, they make all the difference.
At this stage, rather than work on one cat first, I decide to keep moving between the two. Much of that is because I am working on such a small surface it makes sense to keep the same color on the brush. The belly of the female is darkened, the chest of the male is filled in. The underside of the female's tail and her right back leg are darkened. The male's right leg, behind his left leg and his neck are completed.
I think the deep shadow in front of the female's right back leg might be too strong. I'll have to keep an eye on that as I continue.