She was an unknown street photographer of Chicago and died last year. John Maloof discovered her photos after buying tens of thousands of negatives at an auction. A selection of photos are already online. Maloof writes:

After some researching, I have only little information about Vivian. Central Camera (110 yr old camera shop in Chicago) has encountered Vivian from time to time when she would purchase film while out on the Chicago streets. From what they knew of her, they say she was a very “keep your distance from me” type of person but was also outspoken. She loved foreign films and didn’t care much for American films.

The Independent has also written about her.

UPDATE: The online art project Artsy has an excellent page on Maier where you also can buy prints.