I have been starring at this one for days and did not know what to say about it. The setting looks like it was taken at a professional studio. The lighting seems like a single diffused source that I have never seen professional photographers used in portrait.
The one thing that still puzzles me is the baby's right hand. Sandra had very good analysis of the lighting but I am not convinced that the light hit only the palm side of her right hand. The right hand fingers are curled so much, I am expecting to see some brighter spots on the medial side of the fingers which are visible. Is it possible that something was in the way of the light source and the right hand?
The bright spots of her chin looks like light reflection, a piece of glass or shinning metal? I did a restoration of few pictures taken at a banquet and the reflection of the mirror under the centerpiece created light blotches.