In a way, a she-hulk movie poses more problems than hulk does. Most of the time hulk only shows on screen when it's time to "smash" things. This is easier to portray with CGI than say Jen spending most of the movie "hulked out" and interacting in a more day to day manner.
I'd love Jen to come to the big screen, but the story would really have to make some choices about She-Hulk's character. Savage She-Hulk might allow an approach closer to the Hulk, which audiences might expect. The very different character of Jen might be a good twist for the audience. Visually, though, She-Hulk all the time would be tough. CGI all much of the way may not work for audience sensibility, and make-up probably would not cut it at all. They could take the route, as someone mentioned, of Dan Slott's book where part of Jen's job contract was she couldn't be Shulkie all the time. Playing that up could be fun for a film. I haven't seen anything with Ms Harmon, she might be fine, or could be lobbying sore something in the wake of The Avengers and Marvel films in general success.