Thanks for the plug, Professor!
Ben, the last and only info I have about Wendy Walker (it's not recent) is that she was teaching beginners classes in Coventry, England under Pat Stratford Sensei. Stratford Sensei retired a few years ago, ceding his teaching duties to John Gaynor Sensei. It is possible that Gaynor Sensei can shed some light on Wendy Walker for you. He can be contacted by e-mail here
Hope this helps you in your search... Cheers.