There have been so few superhero movies led by females that you can probably count them on one hand. The most high-profile of them all would be Elektra, which opened in 2005 as a spinoff of a Daredevil movie most people didn't care for. It did terribly and basically killed off two franchises at once, and we've yet to another female-led film of the sort since. While Marvel's Kevin Feige has frequently talked about his desire to do one, it may be Sony that beats him to the punch with a Spider-Man spinoff.
According to Deadline, Sony has hired Lisa Joy Nolan (Pushing Daisies) to write a Spider-Man spinoff with a female lead. They've set this movie for 2017, which is the same year Alex Kurtzman's Venom movie is now expected to open. These movies would be filling in the space between 2016's Sinister Six and 2018's The Amazing Spider-Man 3. Ever since The Amazing Spider-Man 2 was a critical and box office disappointment ($700M is disappointing by their calculations), Sony has been shuffling their plan around in order to give more time to reevaluate the direction of the entire franchise.
No other details are available and obviously we don't know which character would be the focus, but one has to think Sony wants this to be a major character who can carry their entire franchise. We're probably only looking at one more movie with Andrew Garfield and director Marc Webb, so don't be surprised if this turns out to be a Spider-Woman or Spider-Girl film.