When you say mean, do you mean biting mean? As far as not letting anyone near her, is she in the cage fluttering around wildly when you approach? If so, the best way to get her to calm down is to walk over to her several times a day and sit near the cage day talking quietly to her until your approach no longer puts her into a panic. Once that is accomplished, start putting your hand on the cage and leave it there while continuing to talk to her until again, she is no longer frightened by it. The next step would be to put your hand inside the cage and leave it there very still while talking gently to her until that too no longer causes fear. Once she is comfortable with seeing you and having your hand in the cage, she will be much easier to train to step up on your finger without causing her any undo stress. This is not something that will happen over night. It will take lots time and patience to earn her trust. Good luck.