Rita DeMara, hoping to show off her talent of engineering, stole a copy of the Yellowjacket costume from the Avengers Mansion through remote control. She clashed with the Wasp who caught Rita modifying the Yellowjacket costume for herself, and the Wasp defeated her easily when Rita collapsed in hysteria the first time she tried shrinking, overwhelmed by the experience.
Later, DeMara was freed by members of the Masters of Evil and they all participated in a successful takeover of the Mansion. When the Masters were finally caught, Yellowjacket was sent back to prison.
Yellowjacket was freed again, this time by her former teammate, the Fixer, motivated by more amorous intentions. Rebuffing his advances, she fled and tried to gain revenge on the Wasp. To do so, she followed her teammate, the Black Knight, whose romantic intentions for the Wasp had been rejected. The Fixer caught up with Yellowjacket, attempting to kill her. Black Knight intervened and Yellowjacket sided with the hero, defeating the Fixer. The Black Knight and DeMara parted amicably, with possible romantic overtones.
Later, during a brief period of time when no Avengers where active, DeMara's Yellowjacket costume received a summons for Avengers reserve members. She banded together with the Avenger reserve members to defeat the High Evolutionary’s intention to jump-start humanity's evolutionary process through worldwide catastrophe. When the crisis was over, she left the company of the heroes.
Yellowjacket returned to the Mansion during a time when people everywhere were being attacked by warped, evil versions of themselves (a plot initiated by the Magus.) At the time, the time-travelling heroes of the 30th century, the Guardians of the Galaxy, had recently taken temporary residence in the Mansion, and a new version of the Masters of Evil, led by Doctor Octopus, attempted to infiltrate the Mansion. Yellowjacket and the Guardians defeated the Masters and the warped versions of themselves. When the Guardians left to return to the 30th century, Yellowjacket used her size-altering powers to "hitchhike" with them, following the Guardians back to their timeline. Yellowjacket was quickly welcomed and she became a staunch member of the team.
In this future, Yellowjacket learned of a dire threat to occur to the Avengers, and she tried to return to her original timeline to warn them. Instead, she was killed by Iron Man, who was operating under the mental influence of Kang, later revealed to be the villain Immortus in disguise.