What if they used She-Hulk instead of Banner/Hulk? Would that still work? She-Hulk shows up and its explained her relationship to Banner?
Ms. Marvel isn't Wonder Woman. She doesn't have a history of 70 years worth of stories, and she's not one of Marvel's top heroes. There are several other characters with a lot more to offer, in terms of distinctive story, history, power set, personality, and designs.
I understand your position on a great role model for young girls, but she won't be any less of a role model if they release her film after Doctor Strange, Black Panther and Namor.
Not saying Marvel will actually do this, but Marvel could introduce Carol Danvers in the SHIELD tv show. Then bring her into her own movie. And like they did with Thor, Captain America, and Iron Man, and what they are doing now with the Guardians of the Galaxy, Thor 2, Ant Man, and the upcoming Avengers 2 and Captain America 2, and Iron Man 3, they could have the Captain Marvel movie at the same time as the Black Panther movie and introduce Namor as the main big bad guy in another film like Avengers 2 (so people first get used to him as a villain and not just another hero).
Its not much of a stretch to think they could use her in the movies right now. SHIELD is freaking out about the alien invasions, her origin is alien and the Kree play a major part in Marvel comics. And like others have stated, Marvel seems to be using characters that fit the stories they want to tell instead of the big names that people will pay to see. Carol's story would fit in with what is happening in the Marvel cinematic universe. Just imagine, SHIELD has already stated they began creating weapons to use against Thor because his appearance on Earth scared them. Now that Loki brought an alien invasion to Earth SHIELD starts the SWORD devision, to combat and prepare for aliens coming to Earth. Carol is part of that, as is Agent Brand. Because of this Carol meets Mar-Vell. Maybe the Kree showing up on Earth could have something to do with Thanos and the Guardians of the Galaxy, and their manipulation of Earth's DNA. But I don't think her story could be told as part of an Avengers story, just like Ultron would only work as part of an Avengers movie (in my opinion) Carol becoming Captain Marvel would have to be told in a solo film, but she should end up on the Avengers.
Carol may not be Wonder Woman, yet, and maybe not have the history, but if they made a movie starring her she would instantly grow in popularity and become a big name like Spider-Man, Iron Man, Hulk, Thor, Captain America. Marvel redesigned her to give her the style with a flashy new costume and name. It would be a good move to bring a female hero into the movies that has the same power level as Thor or Iron Man and right now Carol seems like she could do the job. Once Captain Marvel (Carol) has her own successful movie she will be that much closer to being Marvel's Wonder Woman.
Carol, recently, has appeared in Avenging Spider-Man (2 issues), her own title Captain Marvel, Avengers (Secret and Mighty and others I think), and Spider-Man. She has sort of popped up here and there all over recently I think. But that doesn't mean much, by the time they decide to make the movie she might have a huge successful comic that has been going strong for over 80 issues to 100 issues, or have none at all. Blade had no title when they made it and Green Lantern had a huge successful DC comic and was the center of the DC universe at the time and the movie didn't do so well at all.