Actress Jessica Chastain best known for The Help & Zero Dark Thirty has been up for several Marvel movies over the years. She was one of the final ladies in the running for Black Widow in Iron Man 2 (Which ended up going to Scarlett Johansson) then was up for Dr. Maya Hansen in Iron Man 3 (Which ended up going to Rebecca Hall) but had to turn it down because of scheduling conflicts. Well, she recently spoke with The Guardian about if she still wants to be in a superhero type movie "[I] would love to do a superhero movie! I would have loved to have played Black Widow." She then goes onto to clarify that she doesn't want to just be the girlfriend but an actual hero "The problem is, if I do a superhero movie, I don't want to be the girlfriend. I don't want to be the daughter. I want to wear a fucking cool costume with a scar on my face, with fight scenes. That’s what I'd love." With Marvel actively pursing her in the past it's completely logical they may want her for the long rumored Ms. Marvel role that's in The Avengers: Age of Ultron. That's about as mighty as it gets in the Marvel Cinematic Universe for female heroes!
The thing is Marvel has yet to even confirm Ms.Marvel has a cameo in Age of Ultron. With filming completed it's hard to say if the characters cameo was cut from the final draft of the script. The Ms. Marvel in Age of Ultron rumor has been around almost as long as Aquaman in Batman v Superman.
The Avengers: Age of Ultron hits Summer 2015