A glowing 1920's pinup girl pastel print.

The image is about 12" x 16" in the mat. It almost appears to be an original pastel rather than a print. The signature on bottom right of the print is shown in the second picture. It is unusual. We see a D S then apparently a date. I place this in the 1920's and possibly European. Is anyone familiar with this artists works? (and who is it?) A sideline is that a friend found this in his attic about 20 years ago and wanted me to have it because my wife looks like the subject. She denies the resemblance. Any help will be appreciated. Thanks