I know that she was working on a new book, but I haven't seen any publication info on it. Her description was certainly intriguing though. This is from an interview a couple of years ago.

(It's called)"...Her Fearful Symmetry. It's set in London, in a flat next to Highgate Cemetery. It's got mirror-image twins, mistaken paternity, a little tiny ghost, an obsessive-compulsive, and an accountant. I'm trying to write a modern Victorian novel. It's very early in the project, though, so it's hard to say what it will be in the end."