“A femme fatale, translating to “Deadly Woman” in french, is an alluring, seductive woman whose charms ensnare her lovers in bonds of irresistible desire. Often this leads them into compromising, dangerous and deadly situations.” ~ Wikipeda
Lucy Westenra is a 19 year old from a wealthy family, who I guess you could say, mixed with wrong crowd. She becomes engaged to Arthur Holmwood due to her good looks and sweet temperment. This happiness is soon dashed after she becomes gravely ill and is diagnosed with anemia. In reality, Count Dracula has been visiting her bedside each night for a midnight snack, slowly draining her of blood.
The vampire Dracula, has made Lucy a femme fatale due to the sexual orientation that comes from his extortion of her blood. Marking her as a sexy, desirable woman that he himself has condemned.