Carmilla is a gothic novella by Joseph Sheridan Le Fanu from 1872, before Stoker’s Dracula saw the light.
Laura lives in Styria, she’s the nineteen girl who tells the story. She lives with her father in an isolated castle when Carmilla becomes a part of their lives.
Carmilla looks like a sweet, shy and a little weird girl, pale complexion and weak constitution, but she actually is a vampire. It’s implied that Laura is her next victim, but Carmilla also shows love for the girl and draws out her death instead of killing her in a few days.