Information about Spider-Girl:

Name: May "Mayday" Parker
Secret Identity: Spider-Girl
First Appeared in: Amazing Spider-Man #418 (as baby); What If? #105 (as adult)
Known Relatives: Peter Parker (father), Mary Jane Watson-Parker (mother), May Reilly-Parker (great-aunt; deceased), Anna Watson (great-aunt; deceased), Ben Parker (great uncle; deceased); Ben Reilly (uncle; deceased); Richard Parker (paternal grandfather; deceased); Mary Parker (paternal grandmother; deceased); Mr. & Mrs. Watson (maternal grandparents; possibly deceased)
Powers and Abilities: Spider powers inherited from her father, including a spider-sense, wall crawling and enhanced speed, strength and agility.
History: Born to Peter Parker, the former Spider-Man, May inherited Spider-like powers from her father. While first noticed while she was in her mother's womb, the powers did not manifest themselves until May was 16 years old, the age her father was first bitten by the radioactive spider that gave him his powers. May was called into action when her parents were kidnapped by Normie Osborn, the son of Peter's best friend Harry Osborn and the grandson of Peter's longtime enemy Norman Osborn. Donning the Spider-suit once worn by her "Uncle" Ben Reilly, May rescued her parents and her suit was destroyed. May's parents informed her of her "spider" heritage and that her father and her Uncle Ben were both Spider-Man. May continued her entry into life as a superhero encountering such heroes as the Fantastic Five, the Avengers, Nova and even Phil Urich, the former heroic Green Goblin, now a fellow police officer with Peter. May has also gained a rogues gallery including Mr. Nobody, Crazy-8 and even the Venom symbiote who pocessed Peter for a time. Some of Spider-Girl's enemies have made attempts to reform, including Raptor, the daughter of Blackie Drago, the second Vulture and even Normie Osborn himself. Following an encounter with the villainous Killerwatt, May lost her powers and has relied on her trained skills and a goblin-glider for a time until her powers returned.