The most obvious source of information about Julia Cameron and other
Victorian photographers (and other things to do with photography
etc) is the National Museum of Photography, Film and Television,
Bradford, UK. As a national museum, they have excellent resources,
including a collection of Cameron photographs, one of which appears
on their web-page:
http://www.nmsi.ac.uk/nmpft/
If you ever have the opportunity, it is well worth a visit!