I think this is just a little bit underexposed. A good thing to go for when doing portrait style photos or any photo where people are a large part of the subject is to get their eyes as close to white as possible. There are a number of ways to do this, such as upping the contrast or increasting the brightness.
I think it is composed very well ... seems the light is a bit week on the left and not overall well balanced ... nice faces and you did get the "spark of life" in the eyes :)
This is such a cute "family" picture. Very well composed, very natural looking, thanks to your great little models, and perfect use of black & white / sepia tones. I love it.
Great title. So cute and not cheesy. I like the light on their noses and cheekbones. I like the twinkle in their eyes. Perfect choice for black and white. Nicely done. 8