Baker Street Reader, ca.1866

As you can see, above, this young woman was photographed in the sudio of Window and Bridge, just three hundred metres from Sherlock Holmes' digs at 221b Baker Street, London. (In fact, not only was this photo taken twenty years before Arthur Conan Doyle located Holmes in Baker Street, no.85 was the last number in Baker Street until 1930—as Wikipedia explains here.)

Helping to date this carte de visite, PhotoLondon has an entry (here) for the partnership between Frederick Richard Window and Henry Gawler Bridge, which lasted from 1862 to 1866; and there are a few Window and Bridge portraits online (see Henriette Jelf-Sharp, 1865 here and the anonymous “Standing lady,” ca.1867 here [bottom left]. 

Since we can see the ears of our reader, her hair is up, and her pose is less formal than that of Henriette, it is likely that this photo dates from quite late in the partnership, probably late in 1866.