I personally believe that many pictures just look better in color. Unfortunately, customers want black and white. I usually beat the objection by telling them that I will only give black and whites that are appropriate for that conversion.
Is your picture of a black child? I can't really tell. If it is, then that can cause a problem. When you photograph dark skin people, especially for black and white, a strong right or left light source is useful. It is much harder to create contrast on dark skin which would make a black and white conversion very difficult.
Example of extreme lighting:
If your picture is not a black child then I just wasted 10 minutes. However, when looking for black and white shots, you should be looking for more contrast than you have there.