@Chickenlady
I think you may be on the mark with the 'fallen from grace' hypothesis. Found this:

"The theme of prostitution and the "fallen woman" (an umbrella term used to describe any women who had sexual intercourse out of wedlock) became a staple feature of mid-Victorian literature and politics. In the writings of Henry Mayhew, Charles Booth and others, prostitution began to be seen as a social problem, rather than just a fact of urban life."

Unrelated, but interesting, the 1851 census showed a 4% swing in the demographic towards women which meant there were roughly 750,000 women who would remain unmarried due to the lack of men. These were referred to as 'Superfluous' or 'redundant' women.
( Boss Keloid Got your mother's maiden name tattooed on my arm, Mon 21 Apr 2008, 12:35, Reply)