A name I just recently came to know as well, some of the best candid B&W street photography I've seen.
I couldn't agree more. Fantastic work. They've recently just made a film about her, which looks (surprisingly, as the topic is a reclusive, rather-antisocial nanny) very interesting.
By the way, big fans of street photography might like this thread: http://photography-on-the.net/forum/showthread.php?t=796329
It's at a site called Photography on the Net--a dedicated Canon users site. The good stuff is really good. (It was started around 2009. I don't know much about the first couple of years, actually, but group of people, especially Nmahooch, starting posting a couple of years ago, and lots of "wow!" moments.)