I took an image of myself in the same position as the girl in the image-

I made a selection from two images, one for the body and one for the camera right arm.

I used the eye drop tool to put the same color scheme of skin tone from the original painting onto my image:

Obviously the dress isn't a perfect match either, so I went through and used my swatches to paint onto the dress the tone that I needed. Since the dress is relatively the same shape at the bottom I can save some time and add in the grasses at the bottom of the image and create the banner and text across the frame. I made a custom brush to complete the texture of the dress and push back the bush a little.