The artworks from this artist seem to be connected to an artist using the name or pseudonym Gert Gaggleman, in the past these artworks were attributed to someone named Judie (or Julie) Delcourt. If and what connection there is between the art and this name is yet unknown. There are artworks with a signature Judie Delcourt, so it seems unfair to totally ignore this name.
The time area of the artworks was first to believe being around 1938 but it is more likely they are from around 1950. I was pointed out to this website, the owner did a splendid job in tracing the artist and concluded the artist's name is Gert Gaggleman. Another interesting blog can be found here. Different names pop up: Eva Hahmeyer, and Becker (Gaggleman as well).
Many think chances are the artist was male considering the enormous amount of FemDom artworks I found depicting adult females guiding en dominating young boys, on the other hand the subtileness of the art could show the hand of a woman.
Anyway, this artist has left a very interesting collection artwork, most in watercolor. I hope you enjoy this very large collection.
Read more at Spanking Art Wiki
Since there are so many speculations about the original artist I tried to find signed art, this is what I could find.