Sounds so much like my bipolar son...get her to a professional and then read all you can about her symptoms and what you can do to help her.
Remember, she knows she is different inside and it must be so hard to be her...you are doing the right thing...she needs your support and although it takes all of the effort you can muster, keep at it!! The earlier she understands herself the better she will be able to take care of herself as she gets older! Good luck!