If you want to buy Harriet’s book you could ring the V&A (020 7942 2696) and ask if they’ve got it. They won’t have, but maybe if they get enough enquiries they’ll decide to stock it.
It’s not that easy to get hold of the book in this country. I’ve found it on Amazon US but not Amazon UK nor any other UK site. I don’t think it’s in any mainstream UK bookshops. Bookbrain can’t find it. Abebooks UK brings up a Devon bookseller who has it at a very expensive price. Abebooks global brings up the Oz publisher.