I don't dislike selective color as much as many people around here, but I really don't like it used on baby shots...especially when it's door poorly. And by poorly, I mean that a poor choice was made for what to leave in color.
Selective coloring should be used to draw the viewer's eye to the 'focal point' of the image. With portraits, that is almost always the subject's face and eyes. By leaving the ball in color, you are telling the viewer that the ball is more important than the child and it's hard to know what you want us to look at.
I also don't like it because there is something morbid about a colorless baby.
Now that I've got that out of my system, I'll step off the soapbox.
Rather than placing your lights on either side of you. Try putting one off to the side (this is your main or key light) and putting the other close to the camera axis (this is your fill light).
Use your main light to create shadows/depth and then use the fill light to control the darkness of the shadow areas.