I really, REALLY like this. It's not often that I get to see older women with their kids. I like the composition and the pose, and the choice to make it b&w was a good one.
If I were to change anything about this, I would have the model keep her expression the same, but wait until the baby was laying against her chest. As he is now, he looks kind of goofy and cute, which doesn't quite fit in to the rest of the mood.
Either way, it's a great photo, and both subjects are lovely!