Origin
Introduced in the Marvel Universe as a retcon character, Midtown High student Jessica Campbell was present when Peter Parker was bitten by the irradiated spider that gave him his powers. She had a crush on him, and had just plucked up the courage to speak to him when he was distracted by the bite. She also had a celebrity crush on teen heart-throb Johnny Storm.
Soon thereafter, Jessica was riding in a car with her family when they collided with a military convoy carrying radioactive chemicals. Her family was killed and, after spending several months in a coma, she was placed in foster care and adopted by the Jones family. Months later she awoke, stirred by the first coming of Galactus outside her hospital room.
Jessica later discovered that the radioactive materials she was exposed to in the accident had granted her super-strength, limited invulnerability, and flight (which she never fully mastered). The Joneses re-enrolled Jessica at Midtown High, where she was ostracized by her classmates, especially Flash Thompson. Peter Parker (who had since become Spider-Man) sensed in Jessica a kindred spirit someone who had also lost family due to a tragic circumstance. Jessica mistook his kind attention and lashed out at him, believing he was merely pitying her. At that time she found out she had super-powers.