These Are All of Natasha's Black Widow "Sisters" We've Met So Far

What we know so far about Rachel Weisz's character in Black Widow is fairly straightforward: she, like Natasha, is a graduate of the Black Widow program, although her specialty is something scientific. In the comics, Melina has an alter ego, Iron Maiden, whose hatred for Natasha eventually leads her to become a supervillain and iconic enemy of Nat's.