When we photographed her, we kept the makeup to a minimum as to not hide the freckles. But when you photograph someone in soft light, the freckles get diminished. That's no fun! At first, I used some curves to darken the layer. The exact way you darken it is not important. Choose what you're most comfortable with. But this affected the whole image more than I wanted to. I needed to tone it down.
I added a layer mask, painted in just the areas I wanted to darken (the freckles), and left the rest alone. I used a soft brush to accomplish this.
After painting the areas to darken, her freckles added the depth to the image I was looking for.