I think she's great. Incredible eye for composition and colour, and able to use multiple styles of photography to capture the flavour of the street- candid, portrait, self-portrait, abstract, landscape etc
I do like trying to work out how she did some of her shots. The over the shoulder look is one of her signatures- are they posed, candid or did Vivian attract their attention for the shot? Take the below for example- great subject with red coat and hat, face perfectly lit and framed by the two yellow lines.
In the end, however, it doesn't really matter as the shots are great.