Carmilla

This is a pretty short book.
Although it was written over 20 years before Dracula, it has a similar style.
It emphasizes the romance aspect of vampires more than the horror.
There is a general problem I have with books from this time period in that the culture is so different from mine that it could be another planet.
To start the book, the narrator and her father see a passing carriage have an accident.
In a few minutes, a women leaves her daughter with the narrator for 3 months.
No contact information is exchanged, we don't even get the name of the mother.
This is not portrayed as being unusual, just the sort of thing you did then.