Chip Zdarsky's run on Peter Parker: The Spectacular Spider-Man has introduced Peter's potential sister, former S.H.I.E.L.D. agent Teresa Durand. We use the word "potential" because the evidence of Teresa really being Peter's sister continues to shift, starting with her introduction in the Marvel original graphic novel Amazing Spider-Man: Family Business.

Peter Parker: The Spectacular Spider-Man #302 featured new evidence pointing to Teresa and Peter being siblings, but with any story involving time travel, it left many readers skeptical. However, Zdarsky has let it be known that yes, Teresa really is Peter's biological sister.

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"Yeah, she’s his sister!" Zdarsky revealed in an interview with CBR. "The time travel arc was the perfect spot for her to make the discovery. And now that she knows, she’s got a little bit of what Jonah has: A desire to help Peter, whether he wants it or not. But whereas Jonah will more than likely be unhelpful, Teresa’s a skilled spy, so that can come in handy."

Spectacular Spider-Man #302 saw Teresa discover a secret safehouse belonging to Richard and Mary Parker, with documents containing her birth certificate and a picture of herself cradled in Mary's arms as a baby. It remains to be seen whether Teresa will reveal this new information to Peter, or choose to keep it a secret. Of course, Peter has always treated Teresa as his sister, so she'll always have his love and support, no matter what choice she makes.

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Peter Parker: The Spectacular Spider-Man #304 from writer Chip Zdarsky and artist Joe Quinones goes on sale May 9 from Marvel Comics.