The Jessica Jones a spot on the roster, but the Marvel Comics hero rejected the chance to the superteam for the most heartbreaking reason. In Alias #26, the Avengers ask Jones to SHIELD and become an axillary squad member. But, she ultimately es on the opportunity because she experienced too much trauma to keep being a superhero. The moment is what started Jones' eventual transition from her heroic Jewel persona to a private investigator.
Jessica Jones' history with the Avengers started rocky, but the hero wasn't to blame. The superteam went after the costumed hero, then known as Jewel after the Purple Man mind-controlled her and used her as his own personal weapon. After keeping her as a prisoner in her own body for months, Killgrave sent Jones to kill Daredevil, where she would break free from his psychic hold. But, that didn't prevent the Avengers from trying to take her down, believing Jewel was a villain that needed to be stopped. However, after being knocked out by her friend, Ms. Marvel, Jones woke up with an offer from the Avengers that she would reject.
In Alias #26 by Brian Michael Bendis, Michael Gaydos, Mark Bagley, Art Thibert, Rick Mays, Matt Hollingsworth, Dean White, and VC's Cory Petit from Marvel Comics, Jessica Jones recounts her time as Jewel and coming face-to-face with the Avengers to Luke Cage. In the flashback, it's revealed after battling Earth's Mightiest Heroes, the superteam offered an apology for their attack. Nick Fury says Jessica could be a liaison with S.H.I.E.L.D. while becoming an auxiliary member of the Avengers. Jones rejects the Avengers' offer for one reason: she's done being a superhero.
After being under the control of the Purple Man for so long, Jessica Jones was ready to take a break from super-heroics, rejecting the Avengers' offer for believing she didn't have what it takes. She thanks her fellow heroes for the chance to the superteam but declines. Considering all she had been through as a superhero with Killgrave, Jones needed space. However, she would never get rid of the superhero part of her personality fully, later opening up Alias Investigations but doing things on her without a costume and superhero moniker.
Jones works better by herself or with the select heroes she's chosen to surround herself with like Luke Cage. That's not to say Jessica would have made a poor choice to be a member of the Avengers, but she made the right decision by rejecting their offer, ditching her superhero persona, and going solo. Of course, Jessica Jones would still gladly assist the Avengers when needed, but becoming a permanent part of the team never made sense for the hero.
