This is what we found on Wikipedia regarding the Dewolff:

Jean DeWolff is a character appearing in American comic books published by Marvel Comics. Created by writer Bill Mantlo and artist Sal Buscema, the character first appeared in Marvel Team-Up #48 (August 1976). Captain Jean DeWolff is a police detective from New York City. She is depicted as tough and unrelenting, the result of her difficult childhood and teenage years. She is a supporting character of the superhero Peter Parker / Spider-Man, for whom she secretly develops romantic feelings. She is also the sister of the original Wraith.

The 1985 storyline "The Death of Jean DeWolff" depicts the character's death at the hands of her partner and lover, Stanley Carter, who became the murderous vigilante "Sin-Eater."