Found...

...hidden behind the thick paper on the walls of my under-stair cupboard, the board of a pad of Iolanthe Linen bond notepaper "Suitable for home and Foreign correspondence", with a drawing on the back.

The caption reads "A smart little lady with her hat flying off--------done by Nellie Cleland.

I love her button boots.

There was a flyer in there too, advising the recipient to buy shares in oil.  A bit of research into the date of the flyer suggested that Nellie was probably roughly the same age as my two at the turn of the last century.  

Dear Nellie, we found your picture.