The most interesting item is a summary of a critical article on Brisley's work, which can be found on the Children's Literature: A Guide To The Criticism site. This entry is well buried on a subpage:
BRISLEY, JOYCE LANKESTER (1896-1978)
A375 FACTOR, JUNE. "Joyce Lankester Brisley: An Appreciation." CLE (=Children's Literature in Education), n.s. 10, no. 4 (Winter 1979):163-73.
A study of the Milly-Molly-Mandy stories that, despite their currently unpopular didacticism, retain an appeal. Classifies Brisley as a major "minor" writer.
One of these days, I might even track this article down.
A few other fan sites have emerged. Beebo.org has some interesting things to say about the approach to food in the stories. Someone even attempted a blog in the style of Milly-Molly-Mandy, but gave up after just a couple of entries.
One site makes reference to a shop in the UK town of Tenterden known as Milly Molly Mandy, but offers no further details. However, a since-expired site reveals its address to be 6 Sayers Square, Sayers Lane, Tenterden TN30 6BW. So there you go.
There are lots of references (which naturally I can't read) to a Japanese musican who has taken on the title. A Japanese clothing store has also claimed the milly-molly-mandy.com domain.
Practical stuff: Current Australian pricing (and online ordering) for all the Milly-Molly-Mandy books is available at the Dymock's site; I imagine most larger online bookstores would stock the books.
Random information which I found online but has since disappeared: Actor Ian McKellen identifies the series as his favourite children's book. During a parliamentary debate in 1996, a man identified as Mr Gummer said of another member: " The last time that the hon. Gentleman went into the countryside must have been on a Sunday school outing, and he must have had his eyes closed at the time. He has a Milly Molly Mandy view of the countryside; he got it from children's books."
Proving her ongoing influence on the world of pet ownership, at least two people have called their cat Milly-Molly Mandy, and there are s aimilar number of pedigree dogs, called, oddly, Luvabull Milly-Molly-Mandy and Dajoxx Milly Molly Mandy. Even chooks haven't proven immune.
A final disturbing trend; if you search on the name Milly-Molly-Mandy, it takes surprisingly little time before you run into porn sites. And you thought I was sick for writing Milly-Molly-Trollop!