Great composition and use of negative space on the left. I don't know the circumstances of the shot, but if you get a chance to reshoot and control your lightingm use a smaller aperture to ensure that everybody's faces are in focus, then this will be a killer image.
The contrast and sharpness could use work. All three look a bit washed out. It looks like a "remove color" without tweaking the contrast to make an effective B&W portrait. Pretty good composition, thought it would be nice to have more of the top of the woman's hairline and the whole baby.