"Do you really think for a minute that a nice young lady of 1872 would write that?"

Not sure; I'm certain my grandmother, born ca 1890, wouldn't have put it that way, but I don't know about her mother or grandmother - it seems to me fairly typical of the time, and pretty tame - no more than a roundabout way of saying that she'd be married and, therefore, unavailable. In a similar vein, if a nice young lady of today tells us that she will be the 'Maid of Honour' in her friend's wedding, we don't really take that as a comment on her sexual experience or lack thereof. We do take it that she is single (I think - I haven't been following wedding culture lately).

Going a little further back in time, the term "virgin" seems to have been widely used to mean, simply, an unmarried, young woman, whereas today we use that term only in its literal sense. Yes, there was an "assumption" that if a young woman was unmarried, she "must be" a virgin, but of course this would have been a generally agreed-upon falsehood, people three-hundred years ago being no more innocent or naive than they are today.