Recruited during a membership drive held by the Wasp to find female members in Avengers (1st series) #221.
In Marvel Graphic Novel #18, She-Hulk lost the ability to transform back in Jen Walters. She would remain stable as She-Hulk for many years, although she underwent temporary changes in Sensational She-Hulk such as a weaker gray form or a stronger and more muscular savage green form. In Avengers (3rd series) #74, extended exposure to the presence of Jack of Hearts' zero radiation restored her ability to become Jen Walters. Her strength level increased dramatically through training in She-Hulk (1st series) #9, but she began experiencing trouble reassuming her gamma form after #12. From She-Hulk (2nd series) #1-8, she used a gamma-charger to become She-Hulk, which could only be triggered when fully charged. She overcame these difficulties, retaining her full increased strength and the ability to change at will.
After the death of Bruce Banner, Jen Walters was psychologically distressed and this triggered a new version of her gamma form, beginning with Hulk (4th series) #1. This Hulk was more muscular, with gray skin and green glowing gamma veins. She transformed under stress in this period, and the Hulk had an independent personality from Jen's. Beginning from Avengers (7th series) #1, Jen was further charged by a dying Celestial. The Hulk she became in this time frame was traditional green, but even more muscular than her previous incarnation. Her excess gamma levels allowed She-Hulk to violently expel gamma radiation as heat and nuclear force. Her mind remained Jen Walters, but her diction and assertiveness were Hulk-like at this time. After being manipulated by the Red Room to become a "Winter Hulk", Jen expeled all her excess gamma radiation in Avengers (7th series) #50, reverting to her classic She-Hulk appearance and personality.