I just posted something about this in the misc Blyton forum as I was intrigued by the author's name which I thought must be some kind of homage to Enid Blyton's boarding school series. I just found this on the author:
http://www.collectingbooksandmagazines.com/mallory.html" onclick="window.open(this.href);return false;
Apparently she was a teacher in New Zealand.
Here is a copy of the title page I posted in the Misc forum:
I would be interested to know if anyone, particularly the New Zealanders on here, know/remember this author?