Spider-Girl (May "Mayday" Parker) is a superheroine in Marvel Comics' MC2 universe. The character was created by Tom DeFalco and Ron Frenz as the teenage daughter of Peter Parker (Spider-Man) and Mary Jane Watson, and first appeared in What If (vol. 2) #105 (February 1998). She later acquired her own ongoing comic book, Spider-Girl, written by DeFalco and drawn by Frenz and Pat Olliffe, which was the longest-running superhero book with a lead female character ever published by Marvel before being relaunched as The Amazing Spider-Girl, and later The Spectacular Spider-Girl. Peter and Mary Jane named their daughter after his Aunt May.
Spider-Girl first appeared in a one-shot story in the ongoing series What If. Following positive fan response to the concept, Spider-Girl and two other series (A-Next and J2) set in the same alternate future universe were launched under the MC2 imprint. Although each of these titles were slated to be 12-issue limited series, Spider-Girl's initial sales justified their continuation as ongoing titles.
After initial interest, Spider-Girl drew low sales. However, the book's active fan base caused Marvel to revoke several cancellation announcements. Reprints of the series in digest size trade paperbacks sold well. Marvel Associate Editor Nick Lowe revealed in a November 2005 interview that "Spider-Girl, for the first time, is completely safe from cancellation."
However, despite Lowe's statement, Marvel announced that #100 would be the title's final issue. Although the Spider-Girl title was indeed canceled, the book was relaunched as The Amazing Spider-Girl, with issue #0 appearing in October 2006.