This will take a bit of work & patience. First I would enroll her into an obedience class & possibly check w/ the trainer see if you can enroll her into a puppy socialization class. Second get her out as much as possible, for car rides, walks, etc... everywhere possible. Maybe get a freind or relative w/ dogs & slowly introduce them (on neutral ground like a park or something). Always remember to praise everytime she behaves properly. Has she been this way her entire life? Is she spayed? They say spayed female dogs are the most aggressive towards each other so if so I would start to introduce her to males at first. The obedience trainer should be able to help you out as well as a behaviorist. Good luck