Is this a print or a painting by the Australian artist?
This sounds very much like a print that was brought to me a year or more ago.
These "posters" one of which was by Herta Breit, but these were all by the students of Franz Cizek. Today they are hard to find but one or two show up on the art market here and there. If you have looked for her at all you have probably found as much about about her as is out there on the young artist as she disappears after this period in the histories and remains unlisted today. Thus these child prints are rare and are some what valuable.
"Prof. Cizek's Juvenile Art Class" was at the Kunstgewerbeschule in Vienna. Franz Cizek (1865-1946), a member of the Austrian Secession movement, and was also a pioneer in the field of Child Art.
HIs class produced lithographs, by these young girls, that were such high quality both artistically and lithographically, that they were well noted in the histories. Each of these works today have a value in the range of $400.00 with their provenance, the period and their history. So they are fairly special.
Here is an article that you may or may not have seen but I felt compelled to add it, just to be thorough. I like to add a bit of history when possible.
Best wishes, Dori